Trying vinyl, need some help!

For the last month, I have been searching for a good cd player or transport and thought I had settled on a Mcintosh unit when I started looking and turntables. I found a Roksan Radius 5 with a Nima tonearm that was in my budget so I bought it.
Now comes the problem, the cartridge. There are so many to choose from and they are not cheap so finding one that would compliment the table/arm is a bit intimidating.
My Audio Research preamp has 2 inputs for MM, or I can purchase a dedicated MC preamp.
If anyone has any experience with the Radius 5 please let me know what you have tried.