chief38, the question of building oneself a "special" gun comes up perennially, and while we all agree that in most cases it's not an economically feasible strategy, sentimentality as with your three or acquisition of an exceedingly rare variant or one that never existed can sometimes make it worthwhile. It will seldom be cheap, or quickly done, but if it fills a perceived need or just provides pride of ownership, it can be worth it.
OTOH, the OP asked about buying parts for making a conversion that would not provide advantages over a relatively easy to find model, available on the market at a reasonable price. The project wouldn't have fit any of my suggested categories, so I advised against it, even though I've had a couple of "special" builds done for myself. Mine were just that, "special".
Froggie