I found a few items on "fuel surge" tanks that most of the STI and Honda guys are running. This is basically a high/low pressure system with a very small tank for the FI pump. This looks like a potential solution to the problem without having to build two separate tanks, just place inline and use a low pressure pump to feed from the main tank. Here are a couple links:
http://www.ratdat.com/?p=168
http://sdsefi.com/techsurge.htm
Hope this helps.