Sounds like an interesting project - and sounds like your using all your resources to develop a sound plan.
My suggestions -
CISCO for all router and hub needs - Excellent products and services - and good security.
VoIP - this will save thousands in PBX and wiring costs. CISCO has an excellent VoIP product, but it needs to run on high bandwidth network because of the addition traffic - which can not have lost or delayed packetts.
Copper Cat 5/6 or Fiber to every room or Bed including ER, OR, Labs, Xray, Phy-therapy etc. Personally I would run the Fiber over copper - no interference from equipment in the hospital.
Include a wireless network - this is a ramping up wave in the medical field. Doctors carrying PDA's and are connect to the hospital network - writing orders - and reviewing medical tests is just the beginning. (Wireless bandwidth is getting faster)
Plan for the future of Network monitored beds (were the bed monitors the pt's vital signs), or display screens at each bed with Pt's information and doctors orders. Gigbit into the ER / OR and labs so that - scans, labs, xrays can be digitally recorded and transmitted anywhere in the hospital.
Good luck let us know how it goes...