We have an application that does not support running on a 64-bit OS and also has no need for additional features present in Windows Server. We already have the ML350 G6 hardware but do not see Windows 7 drivers.
Since the latest Windows Server OS is 64-bit only we would be forced to run it on Windows Server 2008 a/k/a "Vista server" which we'd like to avoid if possible.
You can try, some/most of the windows 2008 drivers will work on windows 7.
One option you can do is load Hyper-V Server 2008 R2, its free. Then load your 32bit Windows 7 as a Virtual Machine. As long as you don't have any specific hardware your app needs to work with this should run great and give you some additional flexibility for your server.
Just try the installation. The only thing that's unique to the hardware is the RAID controller. Perhaps the ILO hardware. Check the Windows 2008 drivers if you need... Otherwise virtualized with ESXi and install W7 on top.