Mike good luck with it but hold on to your 705, its really a good machine also.
The Etrac is the best detector I have ever owned. The one real drawback is its balance, to me its like swinging a lead pipe. Theres no counter balance, its like the whole thing top to bottom is the same weight.
I would suggest keeping it as simple as you can. I don't care for programs, pretty much just iron and disc setting appropriate to the site. It does a great job, make sure and work it slow in iron and you mentioned the sunray X5, that's a great coil to have.
You also mentioned Gerrys detectors, I just watched some videos of him setting up the X-terra for park jewelry hunting and also one where he found a ring for a lady. He explains stuff clearly, defiinelty seems like a good guy you got your detector from.
Best of luck, and get hunting while you can, Montana winters aren't to kind are they