I'm kind of the Kaiser at my school's bike club. I also work at a bike shop. Thus, I am charged with buying stuff.

One such charge drove me to purchase a dish stick and tensionmeter from Park. The dish stick was reasonably priced; the tensionmeter was not. Who cares: ain't my money. For my most recent project, the dish stick I used, the tensionmeter I did not. I've only built wheels a couple of times, but tensionmeters are not something that first timers should even be thinking about. Dish sticks are a much wiser investment, assuming that you have a nice truing stand. Hell, a very nice truing stand. I probably wouldn't build a wheel unless I had access to one of the Park professional ones.

All that said, building a wheel isn't that hard. Prepare and give yourself time.