If you are not 24 it may be better to go 20 due to scaling. You would lose fortitude though.
I run with alchemy and mining on my stamina two stacked toons. Although they are not fully stamina stacked when I enter a BG, my alliance shaman has a bit over 3800 health self buffed and a bit over 4100 with fort. Everything popped I have had almost 7,000. Alas, it does not last very long.
The down side to having a high health pool is you get focused a lot, a LOT.
Sweetsidney