If HAPPS has them in stock (Phone in for that) I would go for those, $90 seems to be the avg price for them and their worth every penny IMO.
If HAPPS does not have them in stock I'm not too sure about going with SlikStik direct, lately they have been tripping up on their customer service (shipping related).
Worst case scenario, get a TurboTwist 2 from Groovy Game Gear.