This question is somewhat moot. All classes are equally effective in their own right and since it is a squad based game any shortages that your character may have can easily be augmented with other squad members.
Now as others have mentioned the Biotic (and the Tech) may indeed feel like support classes in ME1, especially at the begining of the game. But by the end they can all lay down the pain in equal parts (through better equipment and assigned talent points).
If you are seriously concerned about only having a pistol (which would seem odd if you are used to playing mage classes) you can do as yx01 suggested and play through as a Soldier one time and get the requisite kills with each weapon which will unlock those weapons for future, new Shepards in the form of a single bonus talent at character creation.
Keep in mind too that if you intend to import this character (or any) into ME2 that you are able to change their class shortly into the game if you desire (which seems somewhat contrary to the plot, but whatever) and in ME2 both the Biotic and Tech classes definately come into their own thanks to combos and some new talents.
So in the end the choice is really yours and depends on what style you prefer when playing squad-based third-person shooter RPGs.
