If you have a device to feed the proper patterns to the crt your end result will be far superior (like the CraftyMech device linked above).
The Spyder colorimeters are decent if you get an accurate unit, some vendors were selling verified units for an additional amount due to a reasonable number being inaccurate.
The i1Display Pro / i1D3 is the way to go with the less expensive colorimeters. There is free software (HCFR) that works with many meters.
Don't buy an older used colorimeter as they tend to drift over time due to their open sensor nature (even when stored properly). The i1DP/i1D3 are sealed and should last much longer.
I have been doing A/V calibrations for years (since the early days of ColorFacts) and have pro level gear (colorimeter/spectro/CalMan) but never bothered to get ISF/THX certification.

-DGP