Advice Please On Turntable Upgrade?

Hi all, I would appreciate some advice and direction on what to look for in the way of a upgrade from a Pro-Ject Debut Carbon turntable for my main system. I will be moving the Pro-Ject to my secondary system.  I want the upgrade to be the best value for the biggest difference in sound if you get my drift.   I just haven't been able to pull the trigger and I have been looking to do this for some time.  I listen to mainly classic hard rock, blues, and old school jazz. my main system is:
Aragon 8008BB  dual mono power amp
Aragon Aurum  pre amp
PS Audio P-300 Power Plant
Wharfedale Pacific EVO 30 speakers
Arcam FMJ 37 Super Audio cd player 
Leema Acoustics Essential Phono Stage
I have a Grado Prestige Silver on the Turntable
There are not a lot of good audio dealers in my area so it's hard to go listen. I appreciate any input. Thanks.