I don't know about the 100, but I installed one on my Tarpon 140 and it made a world of difference. The only problem I can see you having is running the cables if there aren't pre-drilled holes for it. The 140 has pre drilled holes with tubing running from the stern to the footwells. If you can drill those holes and get the cables run, you really shouldn't have a problem. If you want some advice on good hardware and screws to use, let me know...West Marine and Lowes have become my best friends since owning my boat.
haha - yes, love any hardware store! Drilling the holes shouldn't be a problem, just done some for 2 rod holders, the steering system for my feet is the main concern - I've noticed there is a system that you can buy from Wilderness that works on the Tarpon 120 and up, however not sure if it will fit the T100?
If you are talking about the Harmony Rudder system, I really don't think it would be a big problem because all of the cables are adjustable. That $200 + price tag would hurt though if you couldn't return it. My suggestion, if you can, go buy the kit as long as you can take it back, carefully unwrap the pieces and dry fit everything. You will be able to see if it works. If it looks like it won't work, pack it back up and take it back, no harm no foul. Whatever you decide, Good Luck. If you do get that thing ruddered up, could you post a picture? I would like to see how you did it!