I just want to talk Physics for a moment. First of all, there are TWO things to consider when selecting a radiator. These are the metal used in the core and the number of tubes in the core.
1) Aluminum cores are best - that is what MOPAR uses in the OEM radiator, along with plastic end caps. YES it is true that copper conducts heat better than aluminum, but you ABSOLUTELY CANNOT BUY a copper radiator, and that metal is way too weak and would immediately rupture when the system pressurized. The cheap "Copper/Brass" radiators sold by Radiator Barn and other vendors cool WORSE than the OEM, because brass conducts less heat than aluminum, especially after being painted black. (Black paint is pretty much required or the soldered seams will corrode.) If you replace an OEM radiator with a Copper/Brass unit, even one labelled 2-tube or 3-tube, you will lose cooling capacity versus the OEM aluminum core. You may not realize this is a problem until the first hot weather after the radiator change, which could be months later.
Two brands of premium all-aluminum radiators (i.e. no plastic end-caps) are Griffin and Mishimoto. The Mishimoto 2-tube radiator costs about $350 and offers about 20% more cooling capacity than the OEM 1-tube aluminum/plastic, and offers it at low trail speeds, and they are direct bolt-in. Griffin aftermarket radiators can be configured with various numbers of tubes in the core, and frequently require that you trim sheet metal and use a Griffin fan shroud and/or electric fan, but offer up to 50% or more cooling capacity than the OEM radiator, and are reccomended for up to 5.0L 360-hp blown or turbo stroker Jeep motors.
Premium Griffin radiators are $500 and up, as much as $900 with dual fans and shroud and billet caps. But you can order anything including a unit that will cool a hotrod V-8 engine in a Jeep.
2) The number of tubes in the core is a trade-off and Jeep originally shipped 2-tube OEM radiators in TJs, but switched to 1-tube cores in the later TJ model years. More tubes is better at trail speeds, but at highway speed, more air bypasses the Jeep grille. Fewer tubes does not cool as well at trail speeds, but offers less drag which increases gas mileage slightly and cools better at highway speeds or high altitudes, by allowing more airflow through the front grille. Select the number of tubes according to your needs.
1967 Kaiser Commando
2001 Grand Cherokee WJ
2003 Wrangler Rubicon TJ