Thanks @Lisa and @wtg for these comments!
Yep, we're going with a highly recommended company and they do have a guarantee, although I'll double-check to make sure that it's a full one-year.
Yeah, Oct. will be crazy and Mr Sk will be away for some of it so that's why I want to avoid Oct.
Re soil temps, I have a hard time believing we'll get below 40 in the first week of Nov...
I'll report back. We still have to decide on a lot of details (exactly what, where)...