Our mortgage team we have been working with at Sierra Pacific has been very helpful.

Are there any good sponsors that can send me some info regarding deals in the Pacific NW/Texas/Florida area?

My quick observation, unless you're a GC building on flat land I think you're $100-$150 Psf low on your hard construction costs for your expected price range; and that's before architectural, engineering, or other soft costs.The only part of town (LA region) that's achieving $1400 psf and has flat lots would be the flats of Beverly Hills, maybe ocean view portions of Pacific Palisades...Good luck.

I’d avoid Pacific Northwest because of the rain.

The best resources for this question are going to be in regions where the ADU has been embraced as an innovative way to create more places for people to live: the Pacific Northwest, specifically Portland, are the key players here.California is not too far behind because the state has made it much easier to permit an ADU through laws, including the latest in early 2020.The basic answer to the question is a permitted ADU should add 20-30% to the value of your property.

Breeze flowing over cold Pacific Ocean water ... nature's AC :) Maybe not so much in Van Nuys, though.If that 2 BR is surrounded by much larger homes, that could be a good deal for future development and values ... smallest, most run down property on the nicest block I could reasonably afford has been a winning formula for me personally over the years.

And then we also have to remember "Pacific Heights" ...

I think this tenant got his tactics from the movie Pacific Heights (Michael Keaton).

The manufactured homes are improving, but have a ways to go to catch up with manufactured homes in Europe where they are very difficult to distinguish from stick built.The manufactured home provider we consulted (Pacific Manufactured Homes) has a team that has experience in what is necessary to place the manufactured home. 

The metro area is hard constrained on 3 sides (mexico, pacific, military base) and soft constrained (harsh environment) going east.