Not sure what you mean by 192.0.0.x
192.168.0.0/16 is a private subnet, is that the one you mean?
As a rule of thumb, you should plan your network to be broken up into chunks of about 200 devices, and assign each chunk their own subnet, VLAN, and DHCP scope if required.
A reasonable plan would be something like
192.168.1.0/24 -- WAN links (further broken down into /29 and /30 subnets for provider interconnection)
192.168.2.0/24 -- Servers
192.168.2.0/24 -- More Servers
192.168.3.0/24 -- VMotion VLAN/Virtualisation VLAN
192.168.254.0/24 -- Network Management
192.168.11.0/24 -- VLAN11 -- Building1, Floor1
192.168.12.0/24 -- VLAN12 -- Building1, Floor2 North
192.168.13.0/24 -- VLAN13 -- Building1, Floor2 South
192.168.14.0/24 -- VLAN14 -- Building2, Floor1
192.168.15.0/24 -- VLAN15 -- Building2, Floor2
etc....
Your DHCP server should have a scope for each of those VLANs.
You mentioned "proprietary IP devices" - do you mean devices with static IP addresses? If so, get them all reconfigured to use DHCP. There's nothing worse than having to rely on spreadsheets to manage your IP address assignments when the DHCP server can be doing it all for you.