SIP EVO/SIP Performance Exhausts

Hi,Im considering buying a SIP EVO or SIP Performance exhaust for a 1997 T5 Classic with a 152 Pollini expansion kit. My question is this, are there any special configurations with regards to spark plugs, jetting, spare wheel spacing etc that I should know about before I start. For instance is there a better carb to use than the T5 standard that will enhance performance with this set up. im new to this so any help would be greatly appreciated.