Build suggestion

[DecayWolf]

I was thinking about making a Blood mage, because I didn't in the previous DA due RP.
So, I came with this set up.

01 - Hawke Blood Mage/Force Mage: (Dps, off healer, some CC.)
http://biowarefans.com/dragon-age-2-talent-builder/#mir1c0tuh1tesE0G1B0PSw1CvaVwhfr

02 - Carver or Fenris:
Carver: (Stagger, DPS, off tank.)
http://biowarefans.com/dragon-age-2-talent-builder/#4tzeVvok1Y0lX1m0acRirQhSwP
Fenris: (Stagger, DPS, off tank.)
http://biowarefans.com/dragon-age-2-talent-builder/#5zrHVtevZ1z0loka1YoRkMc0ihQS

03 - Aveline (Stagger, Tank.)
http://biowarefans.com/dragon-age-2-talent-builder/#2ztekcR1m0vlM1Rzk0LIpAHKJO

04 - Isabela or Anders:
Isabela: (DPS)
http://biowarefans.com/dragon-age-2-talent-builder/#6bYHLzM1ozYcR0ck1m0RtaVInj
Anders: (DPS, healer)
http://biowarefans.com/dragon-age-2-talent-builder/?dmg=NaN#1zEqiuh1zc0t1M0BC1YRm0GrPSwb

Any help to choose between Isabela and Anders?
Overall how this build is? I only play on nightmare by the way.