I think the better way to shop for a camera for chasing is to look at its features and specs, IE, things like low light capabilities, the ability to lock focus at infinity, ease of changing tapes (some models load from the bottom, a problem with tripod use), ease of ingesting video into a computer, and so on.
Tape format is not that important. Apparently Digital 8 records at the same bitrate as MiniDV and would be acceptable for chasing. Digital 8, however, is rapidy heading toward obsolescence, and it will be harder to find things like new tapes for it down the road. You'll also find that the selection of cameras in the Digital 8 format are small compared to those in MiniDV. If it was me, I would go MiniDV.