I would not bother trying to replace the tank, they'll never get it sealed well enough so it'll stay leak free. They're glued in place then crimped, they are not soldered. When my then-new '97 TJ radiator started leaking at the seal my dealer sent it to a local radiator shop for repair since replacement radiators were impossible to get due to so many having problems. They tried sealing it 2-3 times before I refused to allow them to try sealing it again. They finally installed a replacement radiator which worked fine.
And the last place I'd get a radiator from is 1800radiator. No doubt they'd ship you a cheap radiator that would fail sooner than you'd think acceptable, nor is it likely to cool even close to how well the Mopar radiator does. Avoid too the inexpensive all-aluminum radiators which don't cool worth a crap. They are constructed so shoddily that they all require a liquid epoxy coating be poured inside to stop the leaks and you know how well epoxy conducts heat... not worth a crap.