Firewall/router for 5 static ips

I have recently changed my isp and now have a block of 5 static ips available.
I have 2 standard gateway routers that are each capable of handling one static WAN ip address, and I COULD just continue with that method-
have firewalled server(s) on the switch, and router(s) going to the regular network.

I am thinking about getting one firewall device, however, that can handle all 5 static ips by itself and still run my network. There is one device that Verizon supports and resells for this purpose- Adtran NetVanta 2054 being the model they have.

Not being too knowledgeable in this area (only familiar with the standard home gateways routers) I don't want to spend $300 on something without recommendations though.

Anyone familiar with either that unit or alternatives in the $300 (+ $50 or so) or price range?
I'd rather spend more for something that's worth it then less for junk.

I'm running fine for now, so I am not in any hurry to get something, but I am looking. Thanks.

Could you do that with a linux box?

I could, and I am currently working on getting the server locked down with a firewall anyway, but the idea is to have a lower powered device that is cheaper and less complex to handle these functions.

I have plenty of computers, as well as a total of 4 switches and two gateway routers, but my goal for the server/network stuff is to simplify and improve ease of maintenance.
My goal on the computers is to keep as many as possible as gaming rigs: dedicating one as a server has already dropped me to 5 game machines, and I'd rather not lose another.

To do this you are looking at either cheapo linux box built from garbage components or investing in a real router and not some smart switch device that most home routers are. You are talking big leagues and I would probably look into if you are on a DSL line, a cisco 827 or cable service the cisco ubr900 series. I am not sure as to which cable router is correct for your application as I do not have cable service, but the 827 will work fine anywhere in the USA here, and IIRC for europe too.

These devices run real cisco IOS images, and as such they are a bit more spendy than your average devices, but they will handle EVERYTHING you need to do. If you are like me, and it sounds like you are, buy one of these and you will be set for life.