One thing to keep in mind as far as an insulating layer is that according to this chart is that your metabolism while walking around town is twice that of sitting around camp, so a fleece that is okay walking about Denver may not be adequate for the longer, cooler nights in the fall. MB can be found on sale not infrequently, but REI has sort of jumped on the UL bandwagon with a down jacket, I think, and Marmot's Zeus seems to be on clearance a lot.
For an all-around base layer, I like a capilene 2 zip neck top. Not too hot in the summer, (especially with the zip neck for venting), a decent base layer in the winter. I don't have much experience with MTS fabric, but I do have a pair of REI MTS underwear, and I do like the fabric, I just prefer capilene, but I found Cap 2's at TJ Maxx and on Ebay. For full price, I'd just as likely go with the REI stuff.
I have Marmot Precip full zip pants for my winter outings when I need something fairly durable that I can get on and off while wearing big boots/snowshoues/skis. My precips survived a lot of glissading down Mt Shasta last July, not much worse for the wear, so I can say they are durable for their 11 oz weight in mediums.
I have the 5.5 oz Reeds for spring/fall rains when it's just a hair too cool to let my nylon pants get soaked.
The Wisp, like other wind jackets, aren't going to provide much protection from extended rain. My Patagonia Houdini lasts about 15 minutes in a drizzle. But a wind jacket would replace your softshell, and is nice for extended wear in the mountains(I wore my constantly in the Sierras) over your thin baselayer to prevent heat loss from the wind. Even a breathable rain jacket with pit zips is going to make you sweat too much for that. However, there are several threads on these forums debatig whether a wind jacket is redundant when you're carrying a rain jacket.