As reasonable as you make it out to be, some basics need to be laid down and, IMO, a dealer working on-site can answer many more questions (and provide insight as to infrastructure required) than a remote entity could or would. If OP thought it was a "Home Depot" grade of componentry, he needs to be made aware now that it isn't plug & play, not later.
OP, stop purchasing ebay cast-offs and perhaps pop for a in-home consultation. Ask if the dealer has an issue with owner-provided equipment and if no, then have he/she suggest how to build-up and/or around what you already own. Get off to a good start and you will be rewarded. Many here over the years have gotten hung on the DIY thing and never really embraced the convenience aspect of a functional Control4 system. Of course there are always those who do have fine systems and still complain about lack of DIY-friendlyness