I am unsure what your trans look like...But there should be a port plug on one side that you can un bolt and if a little fluid come out than your good to go. I would just go with an Autometer or supra gauge(they come with sensors) from the local parts store if you don't want anything particular on there($40-60).....and I would go with an F150 pod($29) for your column to avoid drilling any holes on your pillar. That way it could be removed later on and leave no holes. There should be a grommet on the firewall above the brake pedal you could use..I had and empty one. My trans temp stays around 180 degrees but I also have a trans cooler installed.
1996 Ranger 5.0 swap, 20" Kmc Stealth, Trick Flow Upper/Lower, 24lb Python Injectors, BBK 24lb Maf, BBK Air Intake, SCT Tuner From Rogue Performance, Torque Monster headers, FlowMaster Delta Mufflers, Lakewood Traction Bars, Djm Ibeams, Explorer 8.8, Mountaineer Bumper, 30% Tint, 8,000k HIDs, Leds all around, 2002 Expo Leather Seats, 2001 Ranger Dash, 2002 Expo Console, Custom Carpet, Expo Cluster, 2009 Mirrors, JVC Head Unit, 4-6.5" Kickers, Kicker 8" Comp Subs, Jbl Tweeters & Jbl 600 Watt Amp