Dude, please, put down the power drill for just a second.
Go and do some reading around in the project section, see how other people have done theirs. I'd suggest getting it all into position and having a look at what needs to be where, does the compressor outlet point in the right direction, etc? I use a hell of a lot of cardboard and pva myself, it's great for making templates and mocking up brackets, means i can actually test fit stuff without doing anything expensive if it's wrong. Think about the problems you're looking at, the solution is usually simple, for example: If the studs need to be the same length, then cut down a little where required, clean up the edges with a file and extend the thread if necessary, job done. Whatever you do, do it properly, it'll be a better end result for it. Fair play for having a go fella, and good luck.