yes, basically, the colo provider will give you
- space for your server
- network
You might have to buy a switch as well, or if they still have free one, you can rent or buy. Moving to colo is not only buying a server, you will need to buy everything you need.
- your servers, of course

You will need to buy outside and ship to the DC. Some DCs have rent-to-own option
- switches for your servers
- KVM if you want to control your server remotely to BIOS level
- reboot port if you want to hard reboot
- network cable (might be if you are using much)
Manythings need to be considered, for example
- as you need to buy servers yourself, you should buy spare parts for it, in case there is a failure hardware, and you dont want it's going down in a long time
- if you are not in the DC, you will need to pay for the techs in the DC to replace, check your server if it's hardware problem
- hardware upgrading when your customers want to be on a new server