Any recommendations?

All of them.

I was wearing power armor and used rad-x the whole time. Occasionally I popped a rad away.

Depends on your level and how familiar you are with the layout. My first time through I had about 18 rad-away and ended up using all of them along with maybe 5 Rad-X. Of course at some point I lost Ed-E later on and had to revert to an older save before I had done Vault 34 to get him back. I went back again later though and since I already knew the layout and what to expect I got through it using only like 10 and maybe 3 Rad-X.

If you're going in the first time not knowing exactly where to go, what buttons to push and what paths to follow, you're going to need one hell of a lot.
If you're like me, and you went in thinking "Oh look, a Vault! This will be fun!" armed with nothing but combat armor and a 10mm SMG, you're going to need to make a lot of trips. I made about three or four initial trips into the Vault, killing off all the ghouls I could and trying to understand the layout in my head. Once my rad level was too high I would pop back to a doctor and get patched up. Not the best way to do it, but I do feel like I got a better grip of the layout of the place than I would have if I was just wandering around aimlessly scratching my head, popping Rad-Away every three minutes.

lol, this is what i did,in hardcoe mode. my advice to my friends that aren't doing it in hardcoe mode is: get a radiation suit, 10 rad-x's, 10 radaways, 12 super-stims, @ 20 regular stims, some cateye and a coupla 10mm guns(all the ghouls drop 10 mm ammo), but don't take too much 'stuff' with you, cuz you'll have a bunch of booty to carry out when its all said and done

If you've got the Spacesuit and somewhere around 10 Rad-X (which I didn't use all of) You'll never been hit for more than 1 Rad/sec, even right next to the reactor. I used maybe 5 Rad Away and 6-10 Rad-X while exploring the vault, if that.

Just make sure you've got some kind of Rad Resisting suit (Radiation Suit / Spacesuit / Power Armor) to supplement the Rad Meds you'll be taking, otherwise you're going to be popping way more medicine than you should.

Where can I get the rad suit and what are some good vendors to get radaways and rad-x's?

You can find a Rad Suit near Novac (+30 Rad Resist) near the Clark Site across the bridge and South, or you can find a Space Suit (+50 Rad Resist) in the REPCONN Testing Facility where you find the Bright Followers and do the 'Come Fly Away With Me' Quest. Spacesuit is nice because you can still wear a hat/helmet of your choosing as well.

You really don't need to stock up on Rad-X and RadAway to go in as long as you've got a suit and just a couple of each. It should be enough to get you down to the Clinic in the first area and open an Average safe there that has about a dozen Rad-X and 8-10 RadAway.

that's basically what I did, but for some reason, I already had like 20 something rad aways, and when I was leaving, I had like 400 RADS and barely escaped with my life, but I did everything in the vault...

Even with rebrether and Space Suit, I say 10+ for quest and 20+ for exploring.

There's nothing to explore after the quest, (Well, The armory I guess, but that doesn't take 10 Rad Away to walk the 50 feet from the Overseer's to the Armory).

If you need more than 10 Rad Away's with a Space Suit / Rebreather / and Rad X then you have some notoriously bad pathfinding skills. That combo keeps you at 1 Rad/sec the entire way through the vault. Unless you accidentally leave the game on while you're away you're not going to be popping 20 RadAway like that.

Thanks for the info...do I have to complete come fly with me to get the spacesuit or can I just find one in repconn?

I'm running low on Rad-X and Rad-Away...Any reliable vendors? I tried New Vegas Med Clinic earlier and she had none, which was surprising.

I wasn't really ready for that vault and ended up using all 20 something rad-aways and like 10 Rad X. Even then I just did make it out of just under 800 rad poisioning. It was tough though once in the armory it was like Christmas in a radioactive store so much loot for the taking but I did not want to return.

Any unique weapons? Also...do I need to complete the repconn quest to get the spacesuit?

All-American and two sniper rifles among other assorted goods.

there is hidden supply cave .. north of nipton when you see coyoten den and go east up the hill there is little cave with rad suit with .. evolved centaur....

Who usually has a reliable supply of Rad-X and Rad Away....I've been to two doctors that had none!

Yea I'm wondering the same thing...

And the pulse gun but not sure if that is there if you don't have the quest. I don't know about the space suit I missed that.

I found some in a traveling merchant's selling list outside of the Mojave (sp?) NCR base. Rad aways and stimpacks (sp?) are very hard to find in the merchant's and doctor's selling lists in my game. Any time I see rad away in the selling list I buy it and save it for later.

20 of each (with 50+ med skill) should be enough along with the space suit. There is more to be found in the vault and on PC version your followers will teleport to the vault even if you leave them on the strip. Might as well hang around long enough to clean out the joint since you'll have those pack mules around.

STEAL IT MUHAHAHA.

Seriously I've stolen everything of value from every place and everyone I've ever run into and I have those things in huge quantities. Somehow I'm considered Very Good too throughout the game.