Any tips on building an A frame? I found the specs and my husband is a very able carpenter but if anyone has built one and wants to offer any input I'm all ears.

From the DVG America website,
http://www.dvgamerica.com/graphics/A-Frame.gif

More to the point of your question.

Handles or some other way to move the A-frame are nice. The wood should be fairly stout. The dogs can hit it pretty hard. The section from the bottom cleat to the top should be covered with a non-slip material. You should have some method of easily adjusting the height without calling all the neighors over to help -- these things can be heavy. Make certain there are no open gaps that can catch a dog's toenail.

Have a chain or some other kind of connector to hold the two sides in position. They are often placed about mid-point. You don't want it slipping when the dog hits it. You can also mark the chain so it corresponds to common heights.

For training purposes, you could probably skip the 4' 11" width and go with 4'. That will save you a fair amount of wood since US sized lumber generally come in multiples of 4'. 59" is about 150 cm. I suspect that falls in a standard metric size multiple. The height of 71" is 180cm.

It probably goes without saying but make very certain there are no exposed edges that can tear a dog open.

A lot of people use indoor-outdoor carpet to cover the a-frame. I use a good oil based paint and use sand mixed in with the paint and also throw sand on the a-frame while the first coat is still wet. Gives a lot of traction, more so IMO than the carpet.
I still use carpet at the top to cover the gap.

Thanks guys. I was kind of hoping to find a way to make it as light as possible but I think sturdy vs mobility is more important.