Personally, I think its a HORRIBLE idea. A company that can afford to operate a bunch of Beechjunks can afford to spend $20k and send you to FSI, Simcom, or Simuflite for a type rating. That cost should NOT be borne by you up front, because even if they pro-rate the cost back to you over 12 months you've allowed them to MAKE money on the transaction by you personally eating the opportunity cost of the training funds, if not paying interest. Additionally, what others have said about the company terminating your employment is true - you should get, in writing and reviewed by YOUR attorney, an agreement that says 1. they'll pay you back prorated over 12 months, and 2. if your employment is terminated for ANY REASON you'll receive the remainder owed to you within 30 days.

As much as I hate training contracts, a 12 month prorated contract if you leave would be MUCH preferable, in my opinion.

As far as flying the Beechjet goes...it was also my first jet and I had somewhere near 750-800hrs at the time. Its easy to fly, very stiff on the roll and a ***** to land in a crosswind due to lack of ailerons. Climbs okay, cruises right up to .78 after a little bit in the upper 30s. Nice cabin for the passengers, somewhat poor takeoff/landing distance numbers, make sure somebody takes the nose gear pin out before you leave the FBO!