Well, if the deciding factor is cost, then the decision is easy, get the less expensive speakers that you like. Don't overpay used + you can then sell again if needed without taking a big financial hit. Should sound quite good with the kinds of music you mention. Definitely so once the right amp is in place.
Volume sans clipping and dynamics possible are likely where the 30 watt amp with 86 db efficient speakers will have its achilles heel versus the alternative, but might not be a factor in your case. All combos have strengths and weaknesses. THat's why you find so many different ones out there.
Personally, for serious listening, I like to do whatever possible to avoid any chance of an amp clipping. CLipping is audio public enemy # 1, like Kryptonite to SUperman, usually. It is hard to avoid totally with many modern recordings in particular and effects can range from unclear to clearly noticeable. Avoid distortion due to clipping, and many choices then come down to a matter of personal preference. Nobody likes distortion due to clipping yet all hifi rigs are subject to it though, no matter how good otherwise. If dynamics continue to go up in proportion as long as you turn the volume knob up, you are usually in pretty good shape in regards to clipping. if dynamics start to level off even as the volume goes up, then the amp is probably clipping. Teh amount of power needed to prevent an amp from clipping with low efficiency speakers can be quite surprising!
