I'm always on the lookout for PO frame kits, and the one you have is slightly rare in that most are serrated. Yours has an unmolested front strap. I have three sitting in the safe for future builds. They are all serrated, and are the gunsmith kits like yours. Paras have thin front straps at the mag opening, making it hard to chekcer them 20 lines per inch to match the serrations. I prefer the type you have as you can serrate it 40 lines per inch.
Anyway, as for their suitability for a build, they are not as truly straight in the froame rails as a Caspian, as evidenced by the many people who have tried and failed to get a true match fit to the slide and frame. They always loosen up over time, and I'm guessing that's why Les Baer dropped them from the SRP lineup.
If you're not seeking absolute zero tolerance slide to frame fit, then they are a great candidate for a build. I would buy yours in a hearbeat if it were reasonably priced. I say build away.