VPI or Pro-ject

Many good responses, just had to put my thought in... Above all trust your ears. Having heard BOTH the Project and the VPI Prime I love them both, but the things that led me to the VPI was the outstanding customer support, upgradable features that table has such as the SDS, outer ring and pulley changes that make it put it on IMHO as a poor man's HRX. They are now over 10k. 
As far as sound if you haven't heard the Project, expect a very good wide deep soundstage and very warm articulate sound if you use the package that includes the very good Blackbird or celebration cartridge. The very rich sound is also complemented by the very classy wood plinth and built in speed control. The Project offers more of a closed end upgrade path than the VPI. Still a solid choice but I hated the wall wart power supply( sonically reasonable but seems cheap for a 4K turntable). All other things equal, it is otherwise well deserving of a very fine rig. 
I fell in love with the Prime after owning a Classic 1 and wanting the 3D arm. IMHO the VPI arm blows away the Project arm that comes on the Extension table in every way in terms of resolution extension and outright liquidity of the music flow. I heard the Blackbird on that table too. Add the SDS or Eagle power supply and your rig will be in the same class as setups costing 10k or more. The VPI will have an even bigger soundstage and more slam in the lower registers without any bloat at all. The Project will sound a little more rounded but still full and slightly warmer. VPI is even working on options of adding a second arm on this table just like the newly released Avenger. I think you would have a hard time going wrong with either one. Which ever one you choose enlist the help of a decent dealer, they will know how to get the most music out of your investment. Hope this helps🎶🎶🎶

Have to add something else, I have a Soundsmith AIDA on our Prime that is outstanding. If you are not feeling the almost 2k investment, try out the Carmen... It too is an outstanding choice(about $800) The Ortophon 2M black is killer too, only $800 or so too. 

Thanks everyone. 
Not even sure how much to spend on a cartridge but it will definitely be under a grand. 
The Rega P3 was fine but a stop gap. I wanted to pick up a good table and just be done. I enjoy vinyl and want to start including it. I guess it takes me back to my youth. And, is supposed to sound better than digital - right? :/)

For a cartridge, you could take a hard look at an AT OC9/II.  It needs careful set-up and a good phono stage, but will reward the listener far beyond it's price.  I attribute the criticism for the OC9/II to poor set-up or a poor phono stage match up.