I've done a bit of this myself (MF and 35mm) shooting B&W, color and false color IR.

My (rather expensive) 35mm solution would be the Contax G2 with either the 90mm Sonnar or 45mm Planar lens. The G2 provides auto exposure and your choice of auto or manual focus. The G2 is capable of shooting single shot, 2 fps and 4 fps. It will also auto bracket exposures.