Yep, there are plenty of ways to look at the reservoir caps. When I redid this SX-450 two years ago, I decided my power switch cleanup and bridge upgrade were worth trying bigger caps... and they worked fine. I have zero empirical evidence the bigger reserves change the audio performance of the unit, so I have nothing to base a recommendation on beyond "it worked". After two subsequent years of restoring and (sometimes) upgrading the power supplies, I don't think I'd have made such a big jump in capacitance.
In the post above I gave a few options and pointed out the variables one could apply. Your "prudent" in my terms would be "safe" or "original spec" and should be a fine choice. Normally I'd also say "bump up the voltage so the typical operating voltage is only 80% of the cap's rating" to be "prudent" and "safe", but in this case the original spec of 35 VDC is already in that zone.
Bumping up the capacitance apparently is not a problem for in-rush with the upgraded bridge. It certainly could contribute to a shorter life (before you'd have to disassemble and re-clean) of the power switch. Of course, if you do the triac mod, then you've eliminated this downside.
If there are other significantly different options than the ones I've laid out and that you've quite appropriately pointed out, I'd love to hear them.
