Easy, As said the computer controls the ignition. Just leave it in there to control the ignition just disconnect the injector wiring. Maybe a little fluffing round to get it working but I see no reasoning as too why it couldn’t be made to work. Or just go for one of the ignition only megajolt or the likes
For the carbs split the stock manifold just take off the top half and keep the bottom attached and block off the injector ports. Then get some r1 bike carbies as the are held on with rubber couplers.
The manifold is super super simple just a bit of plate to bolt to the ca lower half and some round tube for the carb couplers. Ca ports are 40x32mm at that point so a small squish and maybe a little porting and you’re away. You’ll probably have to make them short to clear strut though.
I reckon it could be done for $1500 if you could fabricate the stuff yourself. If not you could probably get it running for 1500 with a stock exh manifold if you made the bits for the intake manifold yourself and got someone to weld it up. There would be a bit of fiddling with the linkages to make the carbs work too.
Definitely doable though