You know Dan, I don't know if you'll notice any big differences as far as sq goes with this plan, but I get what you're going for. Are you handy with tools and a little bit of wood working? I think you're a great candidate for diy. Just keep the SVS' while you work on your project until it's done. Take your time with it and have some fun.
I suggest this because I'm noticing that you seem to get bored every couple months and look for more stuff to upgrade. I think building your own would be more satisfying, and you'd be more inclined to want to keep them, having built them yourself.