Wattage of amp does not equal amount of air moved, especially when talking about keeping up with drummers! I've been a halfstack man for years; that's down to genre of music (loud & unpleasant) but believe me, my back and transport-organization-skills wish that I was using a Combo.
You should be able to get a smallish venue hearing you with a decent 1x12 combo, unless your drummer is a caveman, then a 2x12 should be plenty. Neither are really "bedroom" amps as your speaker has a sweet spot too. 30 - 50 watts should be fine unless you're looking for headroom.
Fairly recently I played a borrowed 50w Marshall JCM800 combo at a gig. Very nice sounding amp, actually, easily enough gain for classic rock but nice & clear too. The 50w 1x12 combo version of my head (Diezel Einstein) is a great amp but on the expensive side. Mesa does some nice smaller amps, can't really think of anyone else that I've tried.
Very true on your first point, I should clariy with how efficient the speakers are but you hear the guitar due to it's frequencies as opposed to loudness
Originally Posted by hairychris