You should start a Link List instead. A little more work, but I think the returns are better. My LL brings in way more then any TGP I run. If you are still thinking about doing a TGP then I would do a niche one and not just a general TGP. Pick a niche you like and then focus on that. Plus you get way more peple who want to trade links with you when you have an niche TGP.
http://jmbsoft.com/ They have a free TGP script.