I saw this question on another forum. The answer was that if you finished all the main quest and the side missions you can go ahed and beacome a vampire.

That svcks

I'm a level 50 assassin type character. Some of the vampire powers look like they will help my type of character.

On the other hand I have the weapons of the dawnguard in them the crossbow not to mantion the "Enhanced Dwarven Crossbow"

So to be a little bit more specific is there a way to get in the dawnguard and even though I have not finshed all the main and side quests to be come a vampire and earn the weapons ?

I hope there is a solution. Thanks in advance