Summit and Jeg's have them but the cheapest and most complete kit that I found came from northernautoparts.com.That's the one I bought and can say that works very well.I checked the graduations vs. some measured samples at different points of the scale and it seemed very accurate and consistent to me.I believe it was in the $125-150 range.I used to use a calibrated irrigation syringe with very good results in the past but the burette is the way to go for this task in my opinion.
if your not going to be doing heads every day powerhouse products(a division of comp cams) sells a beginer kit for 30 bucks.takes a little longer but if your carefull its just as accurate
