Yeah, do choose Bhelen... you might be surprised how that turns out
. Though in that quest, there really isn't a "right" choice. Both candidates have their flaws.
I like having Wynne... I usually have Morrigan as an offensive caster, while Wynne has more of the healing/supporting/crowd control spells. It works out nicely most of the time. Though I wish this game had more mage companions. There's like five warriors and only two mages and rogues (and Dog, of course
).