Well, I think I've sketched out some rough details, thanks to all the helpful suggestions!

I'm thinking to do:

8 nights Tokyo
5 nights Kyoto
3 nights Fukuoka/Hakata

And will do various side trips.

I couldn't make up my mind for which hotel in Tokyo, so I thought it'd be chaotic, but fun, to do 4 nights Peninsula, then 2 nights each at Grand and Park Hyatts (or maybe just 4 nights at PHT).

I think I'll go for the Hyatt in Kyoto - looks great from the photos I've seen online, despite it being a bit away from the train station, and probably do the Hyatt again in Fukuoka. Gee, can you tell I'm trying to work on building up some Hyatt stays?!

One further question I do have is, if you had to choose just one Onsen to visit from either of these 3 cities, preferably as a day trip and not overnight, which would it be?

Cheers,
Randy