flush mount fuel door

I'm working on a 56 chevy truck and wanted to know if anyone knew the best place to get a flush mount fuel door. I'm shaving the stock one and want to put one of these in its place. I'm talking about the ones that you weld in and smooth out. Not a bolt in one. thanks

the best ones i use and you can weld another peice on the end for the hose
http://cgi.ebay.com/ebaymotors/Pop-up-gas-cap-flush-mount-weld-in-application-only_W0QQcmdZViewItemQQcategoryZ35563QQihZ011QQitemZ320063716609QQrdZ1QQsspagenameZWDVW

you could get soemthing like this

http://www.haganstreetrods.com/index.php?cat=Fueldoors