Thanks, and that's great advice. I'm not pulling the trigger quite yet, I have the J.Tech 3.8w and as you said, I have a ton more research before I spend any more $. I clicked reply on my last post prematurely. I meant to say I'd report back after more research....
As it stands right now, I'm exceptionally happy with the J.Tech, Jay has been a pleasure to work with, his customer service and communication is top notch, and if it were possible to put multiple of his laser on the machine to get me better cutting power, I'd do it in a minute. As for the 7w Sunwin laser, I'm not entirely convinced that even if it were twice as powerful as the JTech I would buy it, given the complete lack of any real documentation or support.
I like the idea of the K40, and I'd even be OK with upgrading to the 50W or 60W version, but the machine size is a bit of a non starter. I'm spoiled with a 1000x1000 work area. To get that same capacity w\ a 40W or larger would take quite a bit of work, or money, or both. I'm a tinkerer, so I don't mind having to add things to the K40, but I'm still put off by the size.
Do I have an answer, nope, but I am going to research the hell out of this problem and hopefully come up with something that doesn't cost $20,000 or take me 6 months to modify \ build.