Rollamite

I need some well priced injectors above 440cc as i will be running 350bhp and dont want them on 90%+ so would like bigger ones without forking out to lateral or rcm for them, ive seen Enterprice 550cc for $190 in the US does anyone know of any distributers or any good alternatives to grey and yellow side feeds?? or if i can convert to top feed?? thanks in advance