Getting a Ragdoll? Are you
? I have nothing against Ragdolls, as they are wonderful cats. But, I think that would just get Gizzy spraying even more than he does. I think he's just one of those sprayers that it doesn't take much to get him spraying and unless you rehome Gizzy and as I recall that wasn't an option you would consider.
As to moving to a house where you'd have a lot more space does sound like a better arrangement that the apartment you're in now. An outdoor enclosure probably would suit Gizzy, but you'd have to make more effort to pet him, etc. when he's not close to you in the house. Maybe reason your bf doesn't want to move is he would feel uncomfortable hearing any amorous sounds coming from the basement or want any to be heard down below from upstairs?
Just a guess! Turn up the music!