I see a lot of those RB-1080s and RB-1090 and RB-991s and RMB-1095s around still kicking after all these years so they cant be that bad.
The Hypex or Purifi suggested are your best bet for those LSI speakers. Without knowing what you actually "power" (almost useless term, but..) requirement is, it is hard to say which model would be suitable, but Polk rated them for 20-300 W (dynamic) so the low cost NC502MP will be able to get them to sound their best.
Class AB amp will do the job too of course, something like the Monolith's 200 Wx2 8 ohms will do but the recommended class D amps will be better if you really want to push them to their limit. All amps (AB, A, or D) rated more than 200/300 W 8/4 ohms with THD<0.01%, 20-20,000 Hz in the price range $1,000 to $infinity will sound virtually the same for those speakers. There are just too much BS/hearsay on the internet so, to save time and money, it is best to stick with specs and measurements that are at least consistent, repeatable, provable facts.
