Graham's 3 way router will work fine for that fixed ip's on the office side router, and the requirement for DHCPd assigned cafe Ip's from the cafe router side.
although taking into consideration what i said about the netmask above and the ability to snoop if you set your mind to it, you can also get your master net<=>router to give out fixed IP's to the office PCs and have it's DHCPd give out the dynamic Ips for the wireless 192.168.1.* parts as well OC for fully private (wireless)LANs.
as for your red edit, its a slight confusion on your part, the 192.168.0.1/
24 (i.e a netmask of 255.255.255.0) to 192.168.0.2 line is infact a direct line to the dlink 2500u router, if thats any clearer!
"dlink 2500u router"LAN-port2<=fixed 192.168.0.2 IP=>WAN-port"dlinkDi624s"
---------- Post added at 10:33 ---------- Previous post was at 10:05 ----------
the reason Zeph's 3 router setup works far better, is the basic fact your wireless LAN is connected to the WAN side of the office routers connection rather than the LAN side of a two router setup, so one LAN cant see the other LAN(s) data throughout.
the only way any router3 LAN PC could see router2 LAN PC data is if you tunneled through the routers on both sides using two PCs if you want that OC, but keep that tunnel data info secure and dont let other cafe users know it.
a multicast tunnel might be useful for you though so you can send video streams to both sides and play it on screens around the place.
a simple "Mtunnel" and copy of VLC will probably work for that id think, something to play with anyway
http://www.cdt.luth.se/~peppar/progs/mTunnel/
http://www.videolan.org/doc/streamin...o/en/ch02.html
use "UDP Multicast" and an IP of say 224.0.0.1:7777 as your stream channel for instance, good for cafe adverts and entertainment streaming for the whole LAN.