ok after reading what u guys said and what there is to do im going to keep the 4 speed and xflow dont messwith it if it works ok :P
but the exhaust needs to go went to see this guy who built my twin pipes on my old celica ( the blue one on his gallary before the body kit whent on tho also is on the product page showing it the underside)
he did a great job and a nice price :D
http://www.zeroexhausts.co.uk/