I went with a "mix-n-match" approach also. If you get the '03 Cobra rear bumper and have the letters filled, make sure they do it correctly. Regular filler in this application will crack with weather changes or if someone bumps into the bumper (i.e. a knee while your getting something out of the trunk). Make sure the rough up the area really well and use a specially formulated compound for bumper repair. Mine also has a layer of mesh that acts as a reinforcement like rebar in concrete.
The Saleen spoiler is a great choice, although I'm not real hip on the 3-piece unless the car has the Saleen rear bumper. Thats just my opinion, though. Either way, expect some extensive prep work on the spoiler. They are far from a "bolt-on" when you get them. Also, I highly suggest ordering through
http://www.speedworx.com I called Saleen directly and they had to be the rudest company I have ever dealt with.
I know I have already talked about the rear bumper, but I just want to mention that using the factory Cobra bumpers is a great idea. They fit great and little prep is needed. The only bad thing about the '03 front is the cost. When I got my '01 shipped for $360, the '03 parts were something like $575 or $600 by the time you got the fogs, brackets, bezels, and the strip across the bottom. But it does look killer. Either one is a great choice.
My hood has drawn mixed reviews when I've posted in the past and I respect everyone's opinion. In fact, there are days that I look at it and have mixed feelings. What I can say is that the fit and finish on the Steeda hoods is top-notch. They are made by a company called Kaenan who just so happens to make a '00 R replica hood that is the same quality but cheaper than the real thing. Also, don't forget if you like cowl hoods that Steeda offers the same hood I have minus the louvers.
As far as purchasing the '03 Cobra parts, I highly recommend
http://www.fordpartsnetwork.com I got my rear bumper and a few other assorted bits from them. Great prices and easy to work with. In fact, I may order a set of '03 Cobra skirts from them fairly soon. If you go with an '01 front bumper for some reason, try GEF Racing. They have the bumper with fogs for $300 +shipping.
And one last piece of advise. Almost all the body parts you are ordering are either oversize UPS or they have to come by truck. If you have your parts shipped to a business, the shipping will be greatly reduced. I saved $40 on the shipment of my bumper by having it shipped to a business.
Hope this helps! And post some pics when you get it done!