Analog upgrade advice.

Cardas blocks? How about getting a big 3.5" (8.9 cm) thick butcher block cutting board to put your turntable on? And swap out the stock feet for Vibrapod Cones and Isolators. I got a pretty dramatic improvement in clarity, dynamics, and lowered noise floor by doing that for my Technics DD TT. I told my audiobuddy, who has a Music Hall belt drive TT and he was really appreciated my advice as it made a noticeable improvement for him as well.

I have a friend who had the Rega 5. The power supply and the Groovetracer bearing & subplatter upgrade took the performance to a point where it sounded better than the more expensive P7.

Really liking my new Salience Jasmine LP 2mkII phono preamp. Very noticeable upgrade compared to my Pro-ject phono tube box II and I bet your phono stage also.

Well Tempered "Amadeus" ($2850 NEW)
Van Den Hul "Colibri Gold LW" ($1500 Audiogon)
Einstein "The Turntable's Choise" ($2600 Audiogon)

IMHO the RB700 is one of the best bang for the buck I've ever encountered...I have the same amp as you and I am very impressed with the built-in phono stage...in my opinion you should get into MC cart (plug into the Luxman) and keep the rest as is until that is done...start with a DL-103R and go from there...next steps would be 'under slung heavyweight' for the tone arm and upgrade body for the cart (alu or wood...)...GOOD LUCK!