Yes and no, with conditions...
Any Toolcat will accept a breaker, but I don't think you'd be well served runing one on the machine. The boom simply isn't designed nor built heavy enough to survive the stresses generated by a breaker. I think the vibration would take a toll on the cab as well. Bobcat does not approve a breaker on the Toolcats and rightfully so IMHO.
As for the Bob-Tach backhoe, I see no reason why you could not run that attachment on your Toolcat apart from the visibility issue. I don't know how well you could see the bucket from the seat of the Toolcat. However, provided you equip your machine with an attachment control kit you certainly could do it. I've run the hoe before on an S185 and was surpised to find that the hoe had a good deal of bucket break-out force, but was very hard to run smoothly due to the switch work and foot work required to make the proper motions. The "crowd" is controlled by your tilt pedal, depth is with your boom up/down pedal and the swing is controlled by the left thumb switch on the right handle. It would take a while to get used to running the thing I believe and it frustrated me quickly. For the occasional user who needs a footer or the like dug, it may be the cheapest alternative to hand digging though. It did have power but it wasn't fast.