1st cartridge upgrade on 1st TT

Would be helpful to see your system. There is a place under your UserID. @tooblue +1. 
 

Good choice for your first table also. 
 

I’m not familiar with. Cartridges in that price range. But many are… I am sure you will get lots of recommendations. But knowing your preamp and Phonostage will be very helpful… and speakers.

RP8 stick with the Rega carts. 

Not sure why anyone needs to see pictures of your turntable. 

Google is your friend.

https://www.rega.co.uk/products/cartridges

One caveat with Rega tables is there’s not much flexibility with the VTA adjustment. You need to buy Rega spacers to help with VTA.
It’s safe to stick with a Rega cartridge but you can try and see if any good MC will fit. It’s important to match the cartridge to the arm. I’d give Upscale Audio a call to see what they usually mount on that table. 

Thanks for the responses!

Still trying to clean up and organize after the move and will post pics shortly.

Rega RP 8 >> Vincent PHO 8 >> Bryston BP 26 >> Ampzilla 2000 2nd Edition monoblocks >> Harbeth SHL5+ 40s (and now a new pair of PureAudioProject Trio 15 Coax)
@tooblue  My phonostage will support MM cartridges. But thought that as a starter, it would need to be replaced too. 

With the RP8 and the lack of VTA you will want to stay in the Rega family of cartridges. They do make some really good cartridges. The suggestion to call Upscale is a good one.

Good luck.