I can't speak from experience with Fuji digital, but I like your idea.
I'm still shooting film in 6x6/120 and 35mm/135 with manual-focus primes, but I've been watching these Fuji cameras for awhile. I could see myself branching into digital with a Fuji body and the 18-55 zoom, as my favorite focal lengths in 135 are 85mm and 28mm. From there, I would probably want to add primes.
More power to you! It sounds like a great setup.
Still shooting film: Medium Format with assorted TLRs; 35mm with manual-focus Minolta SLRs and a Canonet.