clearance on f150

as u all know im lookin for glasspacks...im just tryin to get the best sound and learn from u guys. so please help... PURPLE HORNIES.....they bolt to my manifold...is there goin to be room to run pipe from them after there bolted up?CHERRYBOMB i have one right now.30 inches long. its not poping or cracking at all...someone told me cut my cats off see how it sounds, if not what i want, move it closer to the engine caz it will heat up more and caz it to pop and crack..please help me figure this crap out. i have untill friday this week to make up my mind on what i wanna do, buy purple hornies and get pipe welded to them, or buy another cherrybomb and weld pipe to them with no cats, or buy this dual exhaust combo from JC Whitney that has glasspacks already welded in just bolts on to manifold..... PLEASE HELP!!!! thanks, logan