what brnd oem type rad. to buy?

I feel your pain. My old Jeep Cherokee radiator tank cracked. I bought a replacement rad from o'reilly. What a piece of crap! It was about 1/4 the weight of oem, because it was all aluminum and plastic, whereas oem was mostly brass and copper. The aftermarket rad would barely cool it on a warm day, forget about running A/C. It had a guarantee for 1 yr. It started leaking 1 month after warranty expired. Yeah, I would recommend against buying a rad from O'Reilly.

Mine is all metal, so I tend to think it was a "per application" thing on your Jeep.