Take the turntable down to your local Radio Shack, or other electronics parts store if one is available and see if you can match up the ground jack with a plug they have. Then just about any type of insulated wire should do the trick (say 18 or 20 gauge I would imagine - you could separate a length of el-cheapo speaker wire if you have some lying around, I would imagine). Solder the wire to the plug (or you may find a solderless plug) and the other end just strip it bare to connect to the ground on the receiver / amp.
I also understand that for interconnects (i.e. RCA patch cables) you should, since you have the type that are not hard-wired to the turntable, invest in some decent low-capacitance cables.
See:http://www.audiokarma.org/forums/showth ... erconnects
There may be other suggestions also in this forum.
Although I have not tried them, I thought these might be good as well:http://www.monoprice.com/products/produ ... 1&format=2
RG-59U cabling like these monoprice cables should be low capacitance (17pF/ft) and at $2.11 for a 3-foot set with gold RCA connectors, that would be hard to beat I would imagine, even with shipping.