Sounds good. I like running the tranny fluid through the radiator first. Toyota designed an awesome fluid temperature management system into the Tacomas. Motor oil, and Transmission fluid both exchange temperature with the coolant, and I have never had a coolant temperature problem when I have had to stop several times to give others water for overheating 4x4's in the sand on a hot summer day, this has never been an issue I usually have the windows up and the A/C cranked at this point BTW.) Everything stays nice and stable, but with towing Superchargers, large tires and offroading the tranny fluid can get out of hand so the external cooler ran in series with the stock cooler is a great way to keep those temps under control.
If you live in an area that freezes often then you might want to rig it up so that you can run through the radiator last in the winter. This will prevent over cooling The idea is to keep the fluid in the ideal operating temperature throughout the loads you put it through.
MMMM A clean beach is a happy Beach. http://corpusfishing.com/pinst.htm