I'm with colasblue on this one, I recapped my NAC32.5 and after I got bored of it because it sounded dull and lifeless, made a real difference and brought it back to life. I decided to replace caps "like for like" as close as I could so no mods.
Tants - Don't know what the originals were but I replaced all of them with Kemet T356 series
Electrolytic radials - ROE originals, replaced with Nichicon Muse KZ series, be careful because the KZs are taller than original ROEs or Samwas and the top could touch the solder side of the board next to it (you'll see what I mean when you do the job). I just glued small nylon bar to PCB edge clips to to create spacers and keep pairs of boards separated.
Electrolytic axials - Nichicon TVX series, but in 32.5 these don't have anything to do with signal so specs aren't important.
Inspect all PCB plug in pins and edge sockets, clean with IPA or contact cleaner and plug boards in/out a few times, any doubtful edge connector sockets should be replaced, I could look up the p/n and a source for you but I don't have it to hand.
DIN and BNC sockets - Inspect, and clean with a small amount of contact cleaner and reseating cables a few times, replace any doubtful ones with new Preh ones - but now you're getting into a world of hurt as they are fiddly to replace while maintaining the nice tidy Naim wiring.
Use leaded solder if you can get it, it's easier to use than silver solder, and unless you really know how to solder I wouldn't suggest doing any of this at all, I see some really shitty soldering "blob-a-jobs", dry joints, lifted lands and tracks and it makes me sad to see nice equipment butchered by people who think they know how to solder.
I get all my components from Farnell (Newark Element 14 here in Canada), Digi-key or Mouser depending on price/availability, I would use RS but they don't work out well for Canada, these are all large respected electronics supply companies so you can be as sure as is possible that they will supply genuine parts. I would never use ebay or alibaba or such like for commercially available components, although sometimes if you are looking for NOS / obsolete / niche parts you have to take the risk.