In reference to your question about replacement caps, I have repaired several different types electronic devices over past years, most of them needing cap replacement, blown up, leaking, etc. I have always replaced the standard electrolytics with computer grade high temp 105C and low esr replacement types. In a few cases I went up one voltage level at same capacity, i.e replaced 16v cap with a 25v cap if physical size allowed and capacity was same. As far as changing to different type (aluminum polymer) I can't answer that as I've never attempted it.
Hope it helps.