Hi Brett,
that is one of the earliest Intel Minis, you can't go higher than 10.5.8 on it...
Pre-Installed MacOS: | X 10.4.5 (8H1619) | Maximum MacOS: | X 10.6.8* |
It has the Max RAM that model can use, but isn't going to be pleasant in use with 10.6.8, as well as the very poor Intel GMA 950 Graphics.
http://www.everymac.com/systems/apple/mac_mini/specs/mac_mini_cd_1.66.html
Snow Leopard/10.6.x Requirements...
General requirements
* Mac computer with an Intel processor
* 1GB of memory (I say 4GB at least, more if you can afford it)
* 5GB of available disk space (I say 30GB at least)
* DVD drive for installation
* Some features require a compatible Internet service provider; fees may apply.
* Some features require Apple’s MobileMe service; fees and terms apply.
Which apps work with Mac OS X 10.6?...
http://snowleopard.wikidot.com/
Buy Snow Leopard > http://store.apple.com/us/product/MC573/mac-os-x-106-snow-leopard
Call Apple Sales...in the US: 1-800-MY-APPLE. Or Support... 1-800-275-2273
Other countries...
http://support.apple.com/kb/HE57