No, Samplitude will record til it fills up your hard drive. I've never needed a timer, so there may be one in there somewhere I just haven't found.
For the control part, you would need a Belkin Cat5 Extender. If you go to pricewatch.com and type in cat5 extender, you should get a few listings. The belkin unit isn't the only one, I think there's at least one other one available. The Belkin comes with either 300 or 500 feet of cat5 cable, and includes two boxes. One goes where YOU are, and has connectors for keyboard, monitor, and mouse. For portability and hide-ability, I would get a 15" or 17" LCD that takes analog (db15) video, and put that and the key/mouse in a small, nice looking rollaway TV/VCR stand, or something similar. That way, when you're not recording, you can tuck that and the mics/stands/cables away in a closet and just have a Cat5 wall plate to look at. The other box goes at your computer, and has ports to plug into the key/mouse/video ports of your computer. You may have to buy separate cables for these connections, I don't remember if they're included.
The Belkin extender lets you do everything at up to 500 feet that you can do at the computer, except listen to audio thru the computer's sound card or swap disks in the CPU. Samplitude lets you control everything, including playback, from the screen. If you didn't like the recording, you could scrap it and re-record, without ever getting off the piano bench. You could play back your tracks from the hard drive and listen on speakers hooked to the outputs of the 896 if you wanted to, or on headphones. For this, headphones would be better, as you wouldn't get the ambience of the room twice, once when recording and once when listening. That would cause you to make wrong decisions about the "liveness" of the recording room.
The firewire would be the tricky part, as supposedly you need boosters every 15 feet. I haven't tried this part yet, but plan to when I build my new studio. It will be a separate 40 x 72 building, (helps to live on 10 acres in the country) with high ceilings and separate floated rooms, and will have cat5 to every room, just for this purpose. The firewire will help locate the PC's outside the control room, so I'll just have two burners inside on a firewire hub. With cat5 patch bays in every room I will be able to control the whole studio from any room including the drum room or vocal booth, etc.
Since the 896 DOES have pre's and phantom power, you could use those til you decide to move up, then just go line into the 896 with whatever pre's you add.
Sounds like you're getting closer... Steve