In terms of performance ,your Systemdeck falls in the range just slightly above the Rega Planar3 and below that of the P25, both tables retail for well over the $500 mark.In its day, the Systemdeck competed against the Linn Axis and Manticore Mantra.It is being sold currently in a revised form by Audionote,UK.
I consider the tonearm rewire & cartridge options your best bets. In cartridges, you should consider the Goldring 1022, Roksan Corus Black & Dynavector 10X4II as they are very complimentary to the Systemdeck's strengths.The former are MM designs and the latter, a high output MC.
Best,
Ken