As noted by TeamRX8, you'd be wasting your money to do anything other than OEM given your application. Might be able to find some OEM take-off stuff from someone with a Tein Flex kit or more advanced suspension (such as TeamRX8, for example

), but otherwise it shouldn't be too awfully much at the dealer. And the OEM stuff works just fine with the Tokicos; my car is equipped as such

.
If I may ask as to why you want complete units? Do you want to be able to swap back to stock very easily? As far as breaking down coilovers and putting them back together, the RX-8 is one of the easier cars to work with. Still, I can understand the appeal, having done the job a number of times.