Feel free to contact me by email. You have the address (we discussed the duplicates in my collection last month).
Don't sell yourself short on your ability to build a layout. Nobody was an expert before they tried it the first time. You could also hire a carpenter or cabinet maker to help you learn the skills or to finish a table to your specifications.
I assume you are using maple surfaced plywood because cabinet grade plywood is more stable and flatter than lower grades. Keep in mind you will need to run wires under the plywood to wire both the tracks and the accessories. For this reason I would not secure the plywood sheets directly to your table. Strips of 1x3 lumber between the two can provide the space you need. A frame around the perimeter will also keep things square and true.
One advantage of homosote is that the texture is pleasing when painted. I think I would still use the roadbed Jim Cottzola recommended above, foam tape, or the Johnson rubber roadbed if you can find it. All are easily installed, and all provide a greatly enhanced appearance and additional sound deadening.
We only sell USA Track directly to customers. If you buy track on ebay or elsewhere look for track with ties stamped "USA" or "MTH". The newer MTH track with ties stamped "Lionel" (11-series) was made in China for MTH, and is very poor quality. The old MTH track (10-series) was made by EBR products in New Jersey and is fine. Ross Custom Switches are the best available, and completely compatible with USA Track LLC products (they buy the rails and track pins from us).
Kirk Lindvig, USA Track LLC