Why not just get a 100 disc changer/player? You're not gonna get that many movies on a tivo, and you'll loose the interactivity, menus and the like.
I'm not an expert on this, but all the networking I've ever seen on PVR's is for replay to replay, or an ethernet card hacked into a TiVo, where it can then be tweaked to use your LAN for it's data communications instead of the phone.
If there's a PVR that can record my shows, then use QuickTime streaming to send them to my powerbook over Airport to play in a floating window while I do other work, I'm all over it..... haven't seen that one yet.