Gary,
first off, make sure you visit BT3central.com sometime in the future (I think it is being upgraded right now). That site will help you get the most out of your saw (especially to learn how to align the sliding miter table).
I had a BT3000, and did not use the accessory mounting kit, but picked up a piece of acrylic and made my adapter plate to hang my old porter cable router. It worked pretty well, but I still eded up building my own router table because the ribbed aluminum surface of the table saw would sometimes make feeding smaller stock difficult.
Drilling your ryobi plate should be pretty easy as described above.
Find yourself an old counter top, or some scrap MDF and build a table top. That is all you need for a router table at first. Either pick up the oak park baseplate, or any of the other manufacturer's baseplates and mount that in your table. You should be good to go for a while. My first fence was a 4 x 4 that I cut 2 straight sides on.
As you gain more experience with your router table, you can decide how YOU like to work, and then buy or build the table that suits you best.
Best of luck, and enjoy your saw. It's amazing the versatility of that little machine!