the HT would be fine if you plan to make this a permanent fence, but if you want to look at portable fencing I'm inclined to say that maxi shock is probably the better choice if you want to fence in the entire 40, but personally I've had too much trouble holding sheep in with maxishock, and also, this requires using the reel barrow, and if you are working on plowed soil, the mud sticking to the wheel is a real pia.
I've switched entirely to netting, I now have 30 rolls, and set up 10 roll paddocks which I move as often as needed (for up to 200 sheep). The reason I gave up on the maxishock was because we can get very dry and at times just do not have enough moisture in the soil to make a good circut. The netting is simply more reliable for sheep control, and has the added benefit of helping stymie predators.
But to move any fence, you need reasonably thawed ground. We are colder than you are (unless you are way up north?) seems like those lakes keep you warmer, but I can move fence up until approx Dec 15th. so knowing this you can rotate on those stalks up until the point where you freeze more than 1 inch deep, then need to have enough fence on hand to finish off the remaining stalks.
pulling netting through the stalks is another pia, but it is doable especially if you can flatten those stalks to make a path. I use a 4 wheeler with a 4 x 8 trailer and flatten a path through the turnips (which is similar to having to drag netting through stalks) and it helps.
in summary, if your sheep are easy to control, and you can keep that fence really hot, first choice would be maxishock if you want to do the whole 40 at once, but if you need more control, I'd put up with the hassle of pulling netting through the stalks.
Tamarack Prolific and Ile de France crosses