My favorite all-around rig is a 300+ watt amp with a decent 4x10 cabinet. It should be good for all but the loudest situations in small to medium sized bars or clubs. This should work in large rooms too, as long as the guitars are not stupid loud and you have full PA support. If you can't hear yourself with a 300 watt amp and 4x10 cabinet then you're just too flippin' loud.
You'll have to do some shopping in your area and see what's available in both the new and used markets. Good luck. I love shopping for new gear.
Thank you for your indulgence,