My reply is going to take a different tact from what's gone on before, and ask a core question: "what's your budget for this model?"
Depending upon the source, you can pick up a new OS91 for about $250US, depending on the head type (regular or Byron heat-sink). Figure on the same for the fan unit. Depending upon the condition of your radio, you'll probably need a new set of servoes (metal gear and current generation).
Kit prices are all over the place. Scratch-building or kit-bashing is comparable.
The best thing to do right now is to find out who the jet jockeys in your area are, and talk to them about who's doing what and what their preferences are. You might be surprised and have someone mention a friend who's getting out and selling a complete rig at a bargain price.
Otherwise, select the kit, fan unit/engine combination,radio, retracts and what-nots. Work out the budget and where you can compromise (os.77 instead of the .90) and start shopping around.
This is the voice of experience: I've accumulated an OS.77, Byron pipe, couplers, fan unit, and radio from hanging out at swap meets and eBay. I've got a planset (Fun-Scale Phantom from RCM) and am creating the bulkheads and should have it well under way by the end of February.
Once Toledo is over, this will be my primary project (barring honey-dos and spring arriving early) and should be ready for flight by mid-summer.
Of course, if you're all hot-and-horny with a platinum Amex/MC/Visa card burning a hole in your pocket, the concept of budget does not apply.
...Bruce
