VPI HW-19 Jr. Upgrade


I am considering upgrading my VPI 19 Jr. w/AQ PT-6.
I've narrowed it down as the followings.

1. Upgrade my Jr. to the Mk4
2. Put the Scout platter and bearing on my JR
3. Upgrade to the Scout/JMW-9 and sell my JR./PT-6
4. Change JMW 10 Tonearm

What is my best bet in upgrading from my Jr.?
What kind of sonic improvement can I expect?

It would be very appreciate if you give me an advice.
Any other suggestions are welcome too.
tranmoon
I started out with an HW-19 plinth and MkIII bearing and platter. Then Aries 2 platter and bearing with more sound improvement. Then I built 2" cocobolo plinth with lead load to replace the HW-19 plinth which move my TT into a whole different level. You can pick your plinth design from Teresaudio.com and use VPI platter and bearing instead of Teres. I used classic tonearms such as SME 3009, SME type III, Black Widow, and various Audio Technica Broadcasting tonearms.
I upgraded my HW19 Jr by adding the MK III platter and spindle and noted improved detail especially in the bass.
I got an email from someone here on Agon several months ago about making a plinth for the Jr from kitchen counter material like Corian(sp?). Haven't tried that yet but he claimed it made a nice improvement.
I started with a Jr. w) PT-6 arm and an Ortofon (don't remember model number) cartridge. Upgraded to a Mk III and finally a Mk IV. Still have the PT-6 arm but now use a Sumiko Blue Point Special cartridge. Sounds great --- although the turntable guru at my dealer tells me I really should upgrade the arm. Maybe someday, but for right now I'm more than satisfied.