[F. Gottwald]

i think you should be fine. if you decide to include a single class character, i´d recommend a wizard or, even better, a sorcerer.
i´m currently playing a party of a fmt, jaheira, viconia, aerie, anomen and haer´dalis and it´s one of the easiest games so far since everyone has access to stoneskins apart from viconia (whom i use for ranged support only unless i´m fighting wizards).
you will miss out on the ultimate power trips only high-level mages get but if you can live without the wonderfully smelly cheese of project image and without decimating entire armies within moments using sequencers... go ahead.