Now ya are thinking
Take that model - wing, stab, most of the fuselage are perfect as-is. The carbon structure is sturdy, no doubt well suitable for taking the flight loads.
What it needs now is a 60LX rear exhaust.
You would mount the engine on the nose, inverted. It looks liked the diameter of the spinner and forward fuselage would accomodate a piece of 1.4" or 3/8 plywood for engine mounting. QM40 type rail mount would work nicely.
(you want the engine and pipe inverted - do not disturb the airflow over the top of the wing center section)
Build an engine enclosure/pipe tunnel to sling below the fuselage - which blends/attaches to the existing fuselage.
(you want to avoid modificaiton to the existing fuselage - keep its integrity and strength). The tunnel can be built from wood to start with to get the shape, and with a little help from the guys in the composites forum here on RCU, you can easily build a quick mold to make a fiberglass/carbon part. In that process, you can include a sturdy keel down its centerline to act as a landing skid.
Beyond that... if you want an actual pattern aircraft, contact Carolina Custom Models and get ahold of a Patricia or T2-A or Intruder or similar.... with the right power they can be as fast as you like. (look in the pattern / classic pattern forum). My guess is he will not have any huge reservations selling you a kit.
Bob