More power, used wisely, is not a bad thing.
Possibly the most inexpensive way to big watts, might be class d amps. "Pro" amps for example, like Ashley or Crown.
That or scrounging CL, ebay, offer up, etc. Big watt receivers seem to be bringing big dollars, especially the big 3, Pioneer, Sansui, and Marantz. Since you already have 100 wpc you'd need to look for other brands than those unless extremely lucky.
Which brings up another question, what is your budget?