So any of the storages are ok just go for personal choice,cost etc
Pretty much, Sonos is largely storage agnostic.
The 3 zones,
Front room has home cinema set up
Ok, a ZP90 there then, you could add an additional DAC but personally I'd try the ZP90 using a digital input on the HC amp (if you have any spare, what amp is it?) first and see what you think, you could always experiment with DACs if you can get some for demos later, saves you a little cash in the meantime.
Bedroom has nothing but will be putting speakers in ceiling as this is new extension,Can i have speakers in new bathroom and connect to this player aswell?
Yes you can run two sets of speakers from a single ZP120, although you need to make sure they're all 8ohm speakers to ensure the total impedance doesn't drop below the ZP120's minimum.
Dining room has nothing (this will be a main listening/entertaining room) So will want good sound here
You'd probably want a ZP90 with a half decent stereo amp there then, you could try a ZP120 but I don't know if it'll be up to the quality you're look for there, and if the amp isn't of the digital integrated variety then you'll need an external DAC here (I don't rate the internal DAC on the ZP90 much to be honest), although it's always worth testing it using the analogue outputs first I suppose.
The router is in office of which i can access lounge via cable or i believe Zone bridge
Yes, one device must be wired to the router (Sonos also strongly recommend the storage is wired to the router as well, so bear that in mind), this can be a Zonebridge or any one of the ZPs. A Zonebridge is extra cost of course, but it is only about £70 so might be worth it for the convenience.
Boombox, I already have bose sound dock, Does the s5 link to the rest of sonos via hand controller?
Not via the controller no, the S5 is a fully formed Zoneplayer in its own right, so it links in via the Sonosweb wireless network in exactly the same way any other Zoneplayer does, it's simply a ZP120 with speakers really, that's the simplest way of looking at it.
No kit worth mentioning...