pic: My Rendition of Emperor Swerve

[steelerborn]

I would have to disagree with Adam.

Using larger bearing for the steering in the wheels is not very complex.
Adam's math may be right and you may be able to get away with regular bearings just fine (973 used swerve this year and if they used them it probably is). But I would say that it is not complex at all to design a swerve using larger bearings. There are several ways to decrease the amount of components it takes in the design.

I would say the dynamic load of thrust bearings is a lot greater, than normal bearings, and I usually fall on the side of it is better safe than sorry, which is why I prefer the larger OD thrust bearings. McMaster-carr sells them for a good price, and even have some neutral file formats available for CAD purposes.