Keep in mind, you always have the option to ONLY play with a pistol, or even try to go the entire game unarmed. Depending on individual play style, there may be more or less fun to be had. I usually prefer a silenced sniper rifle/pistol combo for infiltration, then a shotgun for getting up close and personal when the crap hits the fan.
Not sure if all weapons will be able to have silencers on them when the game comes out, but I thoroughly plan to play through at least once going the stealth route with just a silenced pistol and Mike's bare hands.