Once you've worked out how to mount a console (I assume you keep it inflated - as fitting / removing a console and remotes will be a PITA on a regular basis) you'll need:
The helm unit (steering wheel + the bit that moves the cable when you turn it).
A throttle box (e.g. Yam 703)
Throttle and gear cables.
That's all standard stuff you'll find on the net or at a good chandlers/outboard supplier. The bad news is it could easily cost you £300+.
Some sort of wiring loom so your kill cord is at the remotes (and possibly wiring in the choke, and ignition key etc) - a proper wiring harness won't be cheap - but I guess you could DIY something for less.
Then you need the "kit" to convert the engine from tiller to remotes http://www.yamaha-motor.com/outboard/parts/home.aspx
Then input the year/model (I think what you are looking for is on the left as "remo con attachment"). I'd imagine thats a Yamaha only part and so make sure you are sitting down before phoning yamaha for the price!
You'll probably also need an L shaped bar that joins this to the the steering cable/piston - yamaha seem to call this a "steering guide".
Don't mean to be a pesimist - but cost of console + cost of remotes + cost of engine mod, may not be sensible. It may well work out cheaper to upgrade the boat?