Hi George,
The hardest thing with Co Location is if you need direct access to the Server. Some Data Centre's such as Global Switch in Pyrmont do not allow you access directly to the Server due to security Access.
Some of the clients i've got don't need to be directly in front of their Servers so our sys admins act as their eyes and ears for you. Is that an option for you?
Net Registry has a good reputation for their Dedicated Servers and COLO.
I'll PM u my contacts details so you can call him.
When you call you need to tell them:
How many power ports?
IP's?
Monthly Data Transfer
And obviously how many RU.
Hope that helps!
- Bam