
Hmm, not an easy one.
The Technics is a direct drive turntable and these have fallen from grace in recent years, as has the SME 3009 with its nylon knife-edge bearings (you can supposedly improve the arm by moving from original bearings and mounting plate to bronze ones supplied by Analog Tube Audio of Germany). Part of the reason for this fall from grace is down to rumble, but this is mostly historic. Modern plinth technology has largely levelled the playing field.
Arguably, if you like the sound of the deck, keep the deck and improve on what you have. You could try listening to a Rega turntable (probably a P3 or P5, with the supplied arm and one of the Rega MM cartridges). If you find it natural and inviting, you are breaking free from the spell of Direct Drive decks; if you find it imprecise, no belt-drive turntable this side of a Notts Analogue Spacedeck or a Kuzma Reference will come close... and you are talking thousands now.
The cheapest way of getting a better result is as follows: buy a marble chopping block from Asda (no, really), then build a five sided box slightly wider and deeper than the chopping block and about 20cm deep. Seal this box carefully, carefully level it and fill it with silver sand. Place the marble chopping block on top (on the sand itself). Now rest the turntable on top of this mass-damped plinth, possibly using Sorbothane feet between deck and chopping block.
You should also consider trading up from the Nagaoka to a Denon DL103 or DL304 moving coil cartridge. You may need a step-up transformer too.
Any other crazy support plans using home made technology will be greatly appreciated. No Kleenex and spit, please.