Any thoughts if either of these would do well in zone 7 or an alternative pine for this region? Also, any preference between these two and if either would work well for a first pine to work with?
I've no experience with Southwestern white (
P. strobiformis?) other than seeing one growing in the local arboretum, and can't figure a reason why Scots wouldn't work in your area.
The last part of your question is what caught my attention. If you're looking for a first pine, I'd recommend JBP,
P. thunbergii. That's not necessarily a condemnation of other pines, as I've seen fine scots (and mugos, and JWP and ...) but the body of information regarding JBP is large.
Just my thoughts.