Multiple IP router advise

[XBOX4LIFE]

Hi all,
I've been using a 2wire 2700HG-B bt business router for my home network and web/mail server which has done the job until it started failing, so I bought a new 2wire 2700HG-V, this would also do the job but it's got the new 6.1.1.4 fw on it and the bridging settings are locked out and it can't be downgraded...
So i've kinda given up and went back to my failing 2700HG-B but it keeps failing and I need a replacement desperately..
I need a router which is capable of running a private and public network and let me assign external ip address's inside my network, tried about 6 routers now and they all lack the features required (DG834GT, belkin F5D7633-4, thompson V585v7 and a few more thompsons)
Suggestions PLEASE

[Eazi]

Use any router and then build a simple firewall with Smoothwall or similar.

With these you can put in mulitple NICs and create different networks /zones

[Over Carl]

If it's the earlier model with one ssid, I believe it can be downgraded (and wifi can then be boosted from 100mw uk limit to 400mw!)

Also here we use a be supplied router which is doing pretty much what you want yours to do - the unit was supposed to be replaced by a vigor 2820 but for some reason we went back to the thompson. The be box is a rebranded thompson speedtouch - I think it's a 780WL but it hasn't got a model number on it unfortunately.