Responses from bpoletti

Upgrade Suggestions for Rega P2
The best way to upgrade a rega p2 is to trade it in on a different table. Silk purse / sow’s ear and all that. 
Decca London Super Gold Compatibility Question
It should work pretty well with that arm.  Try the SME headshell.  Maybe add a little mass. 
Cartridge new or used ?
Buying a used cartridge depends on the cartridge in question.  If it's a very good cartridge going for much less than the rebuild price, then it might be a good bargain.  I would not buy a used cartridge from someone I don't know / trust unless it... 
New Rega Planer 8 (P8) Turntable - Apheta 2 Cartridge Combo - Thoughts
A used VPI Classic blows away the RP8 at a similar price.  The rest of your system deserves a much better table than a rega.  The VPI fits that.  And if you can find a used VPI Aries, that would also be a great option.  Just in full disclosure and... 
VPI Classic 3 or SME 20/2
I'm a big fan of VPI tables and arms.  Have been using VPI tables for almost 30 years.  They are a great value and provide a lot of musical satisfaction.  But my opinion is that....      There is little doubt in my mind, given that choice between ... 
OPINIONS PLEASE - Phonostage for new Rega P8/Apheta 2 - Sutherland 20/20 or Allnic 1201
In my opinion....None of the Allnic phono stages are anywhere near the performance of a Herron VTPH-2A. Not even close. Neutrality, dynamics, timing, soundstage, image, ease of load matching to a MC cartridge, capable of either mm or mc cart. Alln... 
Next step up from the Sumiko FT-3
I still have an FT3 on an old VPI HW-19/III.  It's a good arm and a very good match to that table.  But the Jelco 750 is a significant step up. 
OPINIONS PLEASE - Phonostage for new Rega P8/Apheta 2 - Sutherland 20/20 or Allnic 1201
There is no reason to buy any phono stage other than a Herron VTPH-2A.  Might as well buy the best rather than trying to decide when to upgrade to a Herron VTPH-2A.Allnic is OK, but not in the same league as a Herron. 
Which Amp to complete my system?
Herron Audio M2.  Honest.  Musical.  Not bright.  Excellent.  [email protected], more into 4ohms, less into 16ohms.   
Next step up from the Sumiko FT-3
GEM has the Jelco 850 series arms.  http://www.hifigem.com/ 
Audiogon member suggestions for a speaker that sounds good at low volume!!!
If you're just going to listen at low levels, you might consider a pair of full range speakers such as Mark Audio Alpair 7P in a "Pensil" cabinet.  Smooth response with very nice extension at both ends.  Doesn't take much power but tey are good en... 
Next step up from the Sumiko FT-3
In my opinion....On an HW-19 IV, a Jelco SA-750 or TK-850 would be a good step up.  I think they are available from George Merrill / GEM Dandy for under your budget.   
Don't buy Allnic H1201 phono stage new.
Everything is based on design.  A tube power supply might be OK or not depending on component interaction.That said, at the price point of the H1200 series, there is no reason NOT to get a better performing Herron VTPH-2a.  And that's not just my ... 
Warmer sounding Solid State
@10000_hz_legend  saod" @bpoletti Warmer sounding because my speakers have a bit of gain in the upper registers.  I am looking for a power option that will balance them out."Sounds like it would be better to get new speakers rather than to mask o... 
Warmer sounding Solid State
Why "warm" sounding?  How about "honest to the signal" sounding?!?