There is a factory fitted efi unit that is rare and lots of money ($500+).

Next option is to buy a weber manifold then buy throttle bodys to suit ($1200+)

Make your own (from min. of $250)

Now for the sales pitch!!

Get someone to make one for you.(like me) Single throttle plate and plenum option $600.
or Quad throttle $900.
Both of these last options i could make and would supply with injectors and fuel rail fitted the runners would have bell mouthed entries and length would be made to suit your application.

Some ideas anyway