Mmm. I don't think you can do this, as installing the 2000 client will overwrite the 7.0 client.
What I do know is that the 2000 client can and does manage 7.0 servers without a hitch. I'm not sure what your issue with that is.
Are you concerned with some of the MDAC components that will be upgraded?
Please give us a little more background on your situation.