Revivng a Series 20 table and arm

I am putting my seldom used Pio Series 20 PLC590 table and PA1000 carbon fiber arm back into regular use. I has sat little used in recent years partly because it has a vintage 1991 AT OC9 moving coil cartidge and my current (temporary) Yamaha receiver only has a moving magnet phono stage. ( I am moving up to a separate amp/peamp combo in the near future.) Here are some pics:
http://i56.photobucket.com/albums/g182/sanlanman/Misc%20Stuff/P8100113.jpg

http://i56.photobucket.com/albums/g182/sanlanman/Misc%20Stuff/P8100115.jpg

http://i56.photobucket.com/albums/g182/sanlanman/Misc%20Stuff/P8100116.jpg

http://i56.photobucket.com/albums/g182/sanlanman/Misc%20Stuff/P8100117.jpg

I still have a DECCA carbon fiber record brush, ultrasonic stylus cleaner and Audio Technica Stylus Cleaning fluid and I just bought the AI record cleaning fluids. Also, I still have the dust cover in good shape, but I removed it before the photos. I have ordered a Besttractor alignment tool from Yip in Hong Kong and have a digital scale suitable for use in setting the tracking force.

Questions:
1) I need to replace the cartridge. I am debating over going with a new AT OC9ML moving coil cartridge and get a separate phono preamp such as a Cambridge 640P or go with an AT 150 MLX moving magnet cart and maybe still get the Cambridge Audio 640P a little later on. Or do you have other suggestions.

2) Is the Cambridge 640P the most appropriate preamp if my budget is under $500.00 ?

3) My tone arm uses a cable with a standard DIN fitting but the cable appears a cheap and a bit basic. I am considering replacing it with the FURUTECH AG-12, but am open to other suggestions.

4) I would like to build an isolation platform, but I am torn between a maple butcher block platform and a sandbox platform. The PLC-590 had flexible spider shaped rubber cushions between the chassis and the circular feet, but I think the foot mounting bolt still transmit some vibrations.

5) The platter is about 4 pounds of machined aluminum and very resonant, but there is hardly any room for something like plasti-clay due to the tight clearances between motor and plinth. The rubber platter mat does a fair amount of damping on its own. Any alternative damping ideas, or am I just over obsessing here?

6) Any other tweaks or suggestions come to mind that would improve performance at moderate cost?

All suggestions are appreciated.