looking online, it seems like you have to go through this complicated process to make the most powerful potion to fortify your smithing and enchanting. Do you really need to make it yourself to have the strongest armor/weapons set? Or can you simply buy it in a potion shop? I have yet to see it in a potions shop.

I always use the Enchanter at the Winterhold College 3rd floor. Theirs a flask of echanting potion on the shelves there that I always steal, and it seems to restock itself.

As for blacksmithing potions - I found one in the Riften Elixir shop for sale.

Yes, you can buy it, and they're better than what you can make yourself at low levels of alchemy. At high levels though... I've made my own that was more than +100% I think, the best I've seen in a shop was +50%.

Whiterun potion lady has it quite often.

Since it gets you crazy high numbers, I definitely prefer to just buy them when I see them as opposed to leveling the skill and spending the perks.

You can buy those from alchemy shops.
If you perk your alchemy and get alchemy gear you can make stronger versions. It's up to you wether the few extra % are worth the time and perk points.

There's two blacksmith pots in Alvor's basemant.

its 7 perks to really get everything you want out of alchemy. And since you go through potions like water (scratch that if you drank that much water in a day you would explode) in this game the +125% to the majority of your potion creation is very nice.

I've only ever found them. They are not common enough for multiple seperate builds, but more than enough for two or three.

At this point I'm not gonna worry about it. I found the fortify smithing by 50% and am now at 799 armor. With 642 armor and a sword with 73 atk took out a dragon in a melee battle within 30 seconds. I should level up to 80 now so the creatures get harder. As it stands, things are a little too easy.

At anything below Expert you probably don't need the extreme boosts you can get from the homemade stuff, but there are still some opponents (notably Dragon Priests) who can be a pain if you're using 'stock' supplies.

I've actually found Experimenter (3) to be handy, but then if I keep alt-tabbing out to an alchemy calculator the game crashes after a while. Practically speaking you don't actually need it though, since randomly plugging in combos at the lab will eventually reveal all the effects anyway and there isn't exactly a shortage of ingredients to experiment with.

Do you need more than the first 5 perks to max Enchantment potion?