I was in the same position as you a few months back. I also work in an engineering field although sourcing the hardware would've not been any easier for me than anyone else on the street.
I finally decided to go with a RepRapPro Mendel kit. I'm now really glad that I did, the build was straightforward and I didn't have to source the 30-odd bags of different bolts, washers, nuts, bearings, springs and odd bits and bobs. And then there's the laser cut MDF and aluminium parts...Plus the quality of the printed parts from RRP is very good, everything fitted very well with little or no fettling.
I am enjoying tuning up the printer and trying to get the best out of it. Would I have had more involvement if I'd gone with a "scratch build" and sourced all the components myself? Possibly. Or I might've given up partway through from lack of time, money or willpower. At least this way I now have a working printer and I can always print parts for a 2nd one!
Cheers,
Tony