No no. I don't think you can use a 10.6.0 disc. You can use 10.6.3, I can confirm that, but I doubt a 10.6.0 disc will work.
Unless you do all of it in Target Disk Mode, you aren't going to get a functioning machine. And by that I mean:
1. Install to the target volume (mounted with TDM)
2. Install the 10.6.4 update to the target volume
You will probably not be allowed to install the Mac Mini 2010 specific update, as you booted OS will likely say it isn't compatible with the computer. So you will have to do the vanilla 10.6.4, boot the Mini and then apply the custom update.
I don't see why the 10.6.0 discs won't work, either way I should know by next week . . . also I thought MacMiniColo stated they got the new Mac Minis working with 10.6.0 disc.
If not its really not a big deal to go out and get a 10.6.3 disc online.
*Update* Regardless I know I can the Mac Mini Server working on regular Snow Leopard without have to run custom firmware, etc. It just getting the correct disc and applying the correct updates from Apple. *Update*
-iGrant