I would never use an A/C condenser for a Auto trans, the volumn of flow is what is needed for cooling and lube of the rear bearings,The hotest oil from the trans, comes directly from the Torque Converter and that oil is probably 50 - 80 degrees hotter than the oil in the trans is. A good Aux cooler is around $50.
An inline filter from Ford is a good filter with an internal magnet, About $15. Just change it every 30K to 40K miles, with a trans fluid change. No need to change the trans filter at a fluid change unless they are half plugged, if it's that way, you need a rebuild anyhow.
A bypass mod would be good in case the filter or Aux cooler would become plugged for some reason, it bypasses the oil to the rear bearings for lube, but not cooling. Ask Ford dealer for the 4R100 bypass tubing. Pic below.
A trans temp gauge is good to have, that tells you if your having a problem within the trans. Install it in the pressure port on the drivers side just ahead of the shift shaft.
As far as any upgrade in the trans guts, it can be/get quite expensive, DYI would be around $600. Unlease you do heavy towing a gut rehab is not needed.
Your 94 should have all the updates in it already. If you have around 200K on it, clutch packs might need replaced, if you notice any slippage in it, or a bunch of junk when changing the fluid.
Mercon V or Ford licensed compatable is recommened.
Heavy towing, a Tugger kit is a mod that helps with shifting, although a Ford trans engineer says there usless and shouldn't be installed.
You have 2WD so a transfer case don't enter into the equation.
Edit: If you have a lot of miles on the trans, you might want to do this, that flushes the torque converter.
http://www.oilburners.net/forums/showthread.php?29296-Flushing-a-E4OD-or-4R100
Hope this helps.