i have looked into this for my venture. why? you know why
you are going to need to cut the pipe rest off the front part of your bulkhead.
the length of flange to piston is shorter than on a srx, this means that if you just made everything the same lengt its power would be higher rpm, not sure how much(insert knowledge here).
mounting this way will make using a stock muffler almost imposible as they fit very tight to the back as it is.
also the angle of the exhaust flange is different so when welding flanges on you would need to angle everything a little different.
if you do lengthen the manifolds so the pipes will be normal length the factory muffler will fit better. you will need to move the hole a little and need to add a srx lower and rear muffler mount. also you will have to cut off the battery shelf from your chain case cover. if you have a battery relocate it to infront of the primary.
the easiest way to do this is to use stinggers

i hate stingers, but if you use them it will make your fit easier and you wont need any muffler brackets and or worry about the shorter length depending on how you do youur flanges.
to start with if you are using stingers use 99up pipes, if you are using stock muffler use 98 pipes.
once your done, do yourself a favor i wish i had done from the beginning, go to a dyno for initial testing, this will save you many hours of screwing around.
i would start with jetting that guys run with power inc center dumps or bender pipes, these would be lower rpm and might get you close.
to get them to fit at the expansion chamber you will need to move the pipe closest to the motor closer and the pipe closer to the bellypan closer leaving a wider space between them for the top pipe to drop down into. also keep tapping with a body hammer to flatten where the shields touch giveing more clearance to get them even lower, it may be nessasary to cut down into the bellypan to ge them low enough. it does look like there will be enough room but i havent done it yet so it may be hopefull thinking. on my viper it was nessasary to cut way down in but the viper has less clearance over the shock on the bellypan than a sx.
dont forget to add a heatexchanger in the back, your gona add 25hp to that sled and power is heat.
as far as saving money, if you worked at mcdonalds for 25hrs at 8per hr you would make up the difference of the cost of the pipes and have a set of pipes you can bolt on, know jetting and clutching without dyno time.
this will be less hours then what you are trying to do.
without dyno time you wont know where to clutch your new conglomeration. you could spend days finding the correct jetting,clutching,rpm combination and that is with a timer.
good luck though, you might beat me to it.
thats all the info i got
if you decide to do it i have alot of cylinders and pistons for sale