Pro-ject Debut 2 upgrade or replace?

Hi everyone

Over the last 10 years or so I have steadily upgraded the majority of my hi-fi and the turntable is the last thing to sort and I am looking for some advice on what direction to take.

Is it worth considering upgrading the tonearm or cart on my current Pro-ject TT or would I be better off replacing it with something else?

If the replacement option is the one to go for I am hoping someone will be able to give me a shove in the right direction - particular things to look for and or avoid.

My budget is around £600 for a complete set up, and I am more than happy to buy secondhand to get a higher model rather than buy a lower model new one.

I hear good things about the Rega P3 and P5, and also the Roksan Radius and Xerxes. I am slightly swayed toward the Roksan, due to having other Roksan gear in my current set up.

My current set up is:

Roksan Kandy K1 Liii Amp

Roksan Kandy K2 CD

Acoustic Energy AE2 speakers

Project Debut 2 SB Phono TT

If anyone can give me some recommendations on decks, arms and carts to look out for as potential audition material that would be great.

Thanks,
David