All I hear is that if you want to be a vampire your best bet is to be a Dunmer
But actually being a Breton is your best bet to negate that pesky weakness to fire
This is due to the resistance to magic
If my research proves true then all fire damage taken is considered magic damage
So all you need to do is feed to not get annihilated by it plus you are resistant to other forms of magic
If that`s not enough for you you can acquire the Lord Stone and completely negate the effects, resist even more magic, and get an armor buff
Then if your a mage, which Bretons are great for, you can hit the magic resistance cap with the help of Alteration perks