I don't have any experience with either company, but did exhaustive research with the
President Home company when we were preparing to build. In the end we didn't decide to go with them, but they have a decent plan. You purchase all your products through them (pooling volume), and they provide you a list of subs -- any or none that you can use, each ranked by others that have used them. If you do a specific portion of the house your self, that's where the sweat equity comes in. The problem comes in when you want to change or purchase better quality materials than what they have, you can get them, but the up-charges start weighing in.
One thing you shouldn't take lightly, is to your statement about the homeowner finding the contractor...while this may seem easy, if your going at it alone, on a single build, you will NOT get a great deal. Most contractors give their best pricing to those that will have more than a single build event...which you can't blame them, and I don't. Here's a case in point, I had a sub bid the plumbing rough- in at $7000! (no fixtures or fixture installation) And while I don't want to bicker about his price, I have less than $1500 in materials. Granted I have a boat load of hours in it, I have more time than money!
Good luck!