Part out the blown engine and sell the carbs, ecu and wiring loom of the 950 to fund the needed EFI wiring and ecu.
Switch over the timingwheel and rejet the carbs for the superduke engine. Then part out the blown engine to minimize the price of the bought engine.
'03 KTM 250sx -- '05 KTM Adventure 950
'00 KTM 250sx -- '03 KTM 450sx -- '03 Yamaha R6 -- '08 KTM SuperDuke R --- '13 KTM 690 enduro R