Okay, lets try to straighten all this out. At home, I guarentee that RedAPPLE, you get 512 kbits/sec. At work you are probably connected to a LAN at either 10 or 100 megabits/sec. You LAN at work probably has a connection to the Internet, and if it were 512 megabits/sec (which is an unusual speed) it would cost your company about $20,000 per month or more. It would have to be a fractional gigabit Ethernet connection. It is pretty unlikely.
Okay, next up, your home network. You get two static ip addresses. Are they globably routable IP addresses (do they begin with something other than 192,172, or 10). If they are private addresses (which the 192, etc are), then you are already being NAT'ed, and one more layer of NAT (some people call it PAT) won't kill you.
SO..... Configure up the following:
apple airport admin ->
Internet Tab:
Connect using Ethernet
Configure Manually
(Enter in all the information into the boxes. You need to fill this out correctly for DHCP to work)
Network Tab:
Check "Distribute IP Addresses"
Airport client computers "Share a single IP address (using DHCP and NAT)
Port Mapping
Let me know if you are running a web server or ftp server from your computer, or if you are running os x and want to be able to ssh into your home computer
Now, connect the cable modem directly to the airport wan port. Connect your switch to the LAN port, set all of your computers to use DHCP. Your done.
It is very nice that your ISP gives you two ip addresses, but if you don't need them, then don't bother.
If you want two computers to use your two ip addresses, you will need to have a very complicated network configuration that I would highly recommend against. You would need to have two computers manually configured with the real ip addresses. Then you will need to turn on internet connection sharing on one of those two computers. You will then need to tell the airport to get an address, on the Internet Tab, via Ethernet and DHCP. Assuming that your ISP is not running DHCP, then the Airport should get an address from your internet sharing computer. (only run sharing on one computer). Then you tell the airport to distribute ip addresses and share a single ip address using dhcp and nat. Then (and this is the crazy part), you need to connect both the lan and wan port to the switch, and the cable modem to the switch, and any nonairport computers to the switch. Because the airport bridges between the airport and the lan port, your statically configured laptop will speak to the cable modem via the lan port (hopefully), and your airport nat'ted comptuer will have a default gateway of the airport. This might not work. It relies on the airport not doing any proxy arp. It is an extremely complicated setup that is completely unnecessary, unless you know exactly why you want to use your static ip address on computers. Millions of people are using the first scenario above, the one that I recommend. They are all happy with it. Very few things will not work, or could not be made to work, via the port mapping. This second scenario is more of a theortical, this might work, and is probably the only way to make it work.