The 3 speed and the automatic will not give you any gains over the 4 speed, as the final drive will still be 1:1. In order to get a better highway gear, you'll either need to change out the rear differential gears or go to an overdrive transmission, like the T5 or the 3 speed with the B/W overdrive.
I took a look at your pix, did you swap to an open driveline? If so, the T5 would be an easy swap, and would keep the floor shifter. Alternatively, there is also a 3.38 gearset available for that rearend. Call Patricks if you want to go that route.
