Im guessing your building a 1st gen camaro? Id say you can't go wrong ether way. whats you budget?
DSE would be my choice on a 1st gen camaro with the quadra-link. and with a hydro frame. if you were building like a chevelle or something id say RS setup would be the ticket I know Chris Jacobs loves his new chassis under his car.
Ether way both are top notch probably depends what you wanna spend with the RS IRS being more $$ than the DSE set-up