I've searched for some further velocloud information (which is scarce, and I don't have the hardware myself), the biggest issues with this hardware will probably be:
- watchdog triggering, this should be relatively easy to resolve
- getting network access, due to the relatively special switch setup. igb apparently needs to get mdio support, so the switch can be accessed and used
--> https://bitbucket.org/velocloud/openwrt/src/master/trunk/target/linux/x64/patches-3.14/444-intel-igb.patch doesn't look too pretty (not impossible, but more akin to porting a mips/ arm/ ppc board, than bog standard x86_64)
Sources, based on a heavily forked OpenWrt (chaos calmer derived), should be available from https://bitbucket.org/velocloud/openwrt/src/master/