I agree that a right Helical clamp is better than strait however helical clampsdo not always acomidate certiain types of fletching. Helical clamps work great on feathers and flexible vanes like Duravanes of just about any length but does not work very well with Bhoning Vanes because they are more rigid and do not conform to the contour of the clamp for these types of aplications it is best to use a strait clamp set on an off set angle.

to answer the question of what kind of Jig to buy in my opinion Bitzenberger is the absolute best money can buy and will be the best for clamp selections but will be a little more pricy around $65.00
Bhoning also makes a great little clamp but I am not sure if they offer Helical clamps with their jigyou can get one of these Directly from Bhoning or you can get one from Bass pro shops for around 30 dollsrs
Greyling is also another good little unit but helical clamps are hard to get for this one as well around 40 bucks at bass pro
for the money applying vanesI would get the little Bhoning use the strait clamp at an off set unless you are using feathers then I would higly recomend the Bitz with the RH Helical clamp.
Greyling