can someone tell me what the differences are? which should I be using for dvcam video

Most SD digital formats like dvcam follow REc. 601, which standardizes a number of things including color. DVCAM records Y'CbCr color, with black level at Y'=16 and white level at Y'=235. The rest of the details you can find in books like Charles Poynton's for example.

But basically, there is only one right way to do it and that should be the default. The PD150 and 170 I believe can add fake setup (called "7.5% setup"?), which is improper and should almost always be avoided.
see http://www.glennchan.info/articles/technical/setup/75IREsetup.html

Your camera doesn't record R'G'B'. Your NLE may have to convert from Y'CbCr to R'G'B' to do image processing... and there are two flavours of R'G'B' in practice.