choosing a turbo

so here is my question in a nut shell. whats too big to fit? im going to be using a SAVSPEED twin scroll manifold, A/C delete. any knowledge out there about sizing for bottom mount? my BW S362 is far too big to fit. i did see a guy with an gt3076R bottom mounted. once i know what kind of space im working with picking a turbo is much easier. any input would be greatly appreciated!