im not to shure if there is a webber there, ill have to check tomorrow, from memory there is a dellorto and a stromberg.
either would be totaly sufficiant for what you want, its just a matter of fabricating the necisary manifolds ect..
pretty straight forward stuff.. you will have a hell of a time making the thing run right.
is a factory t25 t28 wastegated at 7-8 psi?