I have a pen that is made with cattle panels and tpost. It works great. I use it mainly for a few hours on the weekends to let the horse graze the rich grass we have in the front yard. The thing I really like is that it is easy and inexpensive to add on to. I don't see why you couldn't use it for a round pen also.
As for moving it - We bought the extra long tpost and I think they would be a bear to move!! The smaller ones are not too bad. I bought 1/2 of it from someone that used it for camping and then added on the extra panels and post to extend the size. I think I would go with the shorter post for Taz - he is not a fence pusher and we are always around when we turn him out in it.
