I bought that exact Imperial/Betson model from gatorcade.com; the company shipped quickly, no problems there. This TB is the biggest model case-wise, compared to all the happs models and wico 3".
The wico 2 1/4" should fit the happs 2 1/4" mounting plate, but havn't tried it myself. The ball itself isn't as nice as the 3" models, but quite good anyways. Other thing, it doesn't come with any wires, while the 3" ones do. It's cheaper because it's the lower in quality of those you listed, IMO.
Bob Roberts also has the 3" model. Both are the older happs models (1/16" lip). The two 3" TBs you listed are "high lip" models with 3/16" lip.
All the the TBs are arcade quality and you should be happy with them. I'd go for either of the 3" TBs, or the wico depending how much money you're willing to spend. The happs/atari 2 1/4" isn't worth the money (but I don't have one).