get that aluminum one for 31.99 at this address
http://www.autozone.com/servlet/UiBr...7C%7EEA%7C%7EB
O and ok from what you said about the tread, maybe it is about time to get them replaced.
If the driver seat supports are broken down, the easiest route would be just to buy a used seat from a junkyard or something. It should be less then 100 bucks. That is, if it's even enough of an issue to replace. You might be able to rig up a pillow or piece of foam and strap it to the seat to push you forward enough. Just be creative.