My recommendation is to go to Incra, and buy their table saw router table add on. They have done an excellent job of engineering the table, the insert, and the overall function, with great results. I own one now, and use it almost daily.
A couple of years ago, I built my own table saw add-on for my Ridgid Contractor Saw ( similar to your Jet). I used 2 layers of Melamine covered particle board for the table, and attached an AL angle bracket to the rails, using the MCLS template and instructions. Here are my results:
1. Building the table top and using the guide and template to cut the openings was straight forward. Took two shop sessions.
2. After I got the system working, I found that the phenolic router plate was bowed concave, and was not up to accurately supporting my Triton router.
3. I called MCLS, they were good enough to replace the plate with an AL one, which was better, but still needed adjustments to the plate insert for height.
4. After all the work and adjustments, I came to the conclusion that i got what i paid for. Even though the cost of the Incra table saw add-on is a bit more, ($220 on sale including the router plate), you will find it is money well spent, and your projects will reflect the accuracy we all are striving for.
Here is a link to their site. I hope this is of help. Good Luck!
www.incrementaltools.com/28_x_32_TS_Router_Table_with_TSRTHW_p/tsrt2832r.htm]28" x 32" TS Router Table with TSRTHW