Go with Edelbrock, they come with all the piping to the cat, and they are less expensive than the JBA's. I have heard from several GM owners and they complained about Leaks from JBA. JBA makes better Ford products than GM.
Ya get what you pay for. If JBA's are installed right and with care they'll
stay leak free. I took my time doing mine and they're flowing sweet
with no leaks. Replacing the POS gaskets that come with the JBA's
is the trick. Fel-Pro, Genuine GM, Mr.Gasket Ultra Seals etc is where
the leak free install happens along with follow up torque of the bolts.