You can do a relatively simple power build for about $700(rebuild kit and O/S valve head) + block machine work. A buddy went this route a few years ago using Engine Builder parts along with a Webber carb. It was a definitely night and day difference, rather than pulling mountain grades in 3rd(37's & 5.29's), he could pull them in 5th, or 4th when loaded down with camping gear.
Webers are kick ass on the hwy. I loved mine on my old Nissan. But from the sounds of it, the new ones aren't that great.