Try the new amp with the "old" speakers first, it may be all that you need right now.

I'd recommend the QSC amp for this purpose, their designs are seeming to be the most robust out there in the field at this point in time, less complex design = less repairs in the field.

It is better to use a power amp that is actually rated at higher wattage than the speakers are, rather than one that is anemic. The lower power amp will be forced into clippling sooner and that can burn speakers faster. Just don't overdo that idea too much. For example, the aforementioned 200 or so watts is likely to work just fine. I'd consider any amp capable of making up to twice the rated power of each speaker as being okay.

--Mac