Exhaust - What to do???

[Enoch]

Hi guys, I now have my engine and box in and have started wiring but want to turn my attention to the exhaust - the idea being to then complete the wiring and stir the beast in to life
I am using the I4 DOHC and would have to modify the downpipe to make it fit or buy a 4 branch manifold kit such as one from pepper performance. Has anyone gone this route? I can't see how the 4-1 collector could be welded without specialist gear - it looks virtually impossible to get round the pipes to weld them in place, particularly with a mig welder
I want the pipe to come out quite low in the car so it goes through the side panels and not through the bonnet. Pepper do a 4-2-1 and a 4-1 but I don't know which one to go for or whether to mod the original and save myself 100 quid.
Any thoughts or guidance would be much appreciated.