I have just created a JP1 upgrade for Sony Dream Systems and am waiting to see if a JP1er with such a system will confirm that it works.
Assuming it does, I could pre-program a remote with this code for you. I have several to chose from, so it depends on how much you want to spend and how advanced you want the remote to be.
If you want a remote especially designed for your Tivo, you could chose the URC-6131 "PVR" remote, which is $25.
If you want a cheaper remote, the URC-6012 is $15 and the URC-8011 is $20.
The 8 device, learning URC-8811 is $25 and the RCA RCU810 is $30.
Rob
http://www.hifi-remote.com