Which: VPI HW19 Jr. or III vs. REGA P3 and P25

Sorry, lets put some tonearms on these puppies:

P25 with the RB600 vs. HW19 MKIII with the RB600
P3 with the RB300 vs. HW19 jr with Audioquest PT 6

Having heard both the Rega and VPI turntables many times, and speaking as a long-time owner of the HW-19 (first the original, then upgraded to the Mk3, and finally upgraded to the Mk4 with a Super Armboard), I'd recommend the VPI over the Rega in both cases. The HW19 Jr. gives you an excellent starting point that is upgradable all the way to the Mk4, but if you have the cash, I'd go with the HW-19 Mk3 with either the Rega RB600/RB900 tonearm, or the VPI JMW10.

try an audio note turntable 1 with an audio note arm 1..you may be pleasantly surprised

I would recommend the P25 over the VPI, simply because it just sounds more musical, especially in the area of PRaT.

For some very interesting insight into Tonearms read this thread. Good luck to you on your adventure.
Strange tonearm tweak Long