The Bronze engine is different…it uses silver plated wire, and the cost difference is trivial between stylus and cartridge, so get the whole Bronze. I too recommend keeping the RPM1 and addressing you upgrade itch with a cartridge. For under $500, the Bronze is where I’d go. The “Clever Clamp” is another record clamp suitable for your Table.
https://elusivedisc.com/clearaudio-clever-record-clamp/
for isolation and leveling: a set of 3 Funk Firm Boing feet should screw into the threads used by Pro-Ject for the stock feet