Howdy Scott. not sure PM got to you so this might be redundant. For a truly easy and good fit, I have used steel mountain bike frames. The standard kits fit perfect and the frames hold up great. Only down side is the MTB handle bars have you sitting/leaning forward. (hate the seats too) But makes for an easy build. Also MTBs normally have better brakes and are built a lil tuffer. Again, in most and that's just a generalazation. But I still have dreams about my first MB built on an old steel MTB. thing was awesome and a really easy build. Don't worry so much about having to do mods. in a year you will be amazed at the cool things you, your self came up with.
Almost all builds will take some tweeking. You can do it! Run into any problems, some one else has and you have all of us to ask!
Please let me know how you are doing.
Dan