Your paying for a much more finished turbo. The SP turbos includes a downpipe. Ceramic coating on the header, turbine housing, and downpipe. The compressor housing is also polished. My friend had a T78 and he said his next turbo will be an SP63 with stock fuel, intercooler, and MAF. I use the stock MAF, though I do have a FMIC. It's not a problem running the stock MAF and intercooler, but you will make less hp. You could still hit 500rwhp with the stock intercooler, fuel, and MAF.
You work for a big parts company, maybe you can get your suppliers to give you all the parts you need for a fuel system.
Later, Steve