to me it would depend on how much sun you are talking about and how much water you are able to provide. There are periods in the hot summer when mophead and lacecap types just look a little sad, and bunched together in a hedge makes it look even sadder to me. This happens even at Aldridge Gardens near where i live, and they use their lake to irrigate. They can also take a few years to get established. I've been waiting for some "endless summers" to take off for a few years now.

I think the Oakleaf types are more forgiving and spectacular in groups, and
work well in somewhat shadier places, and have peeling, interesting bark. for a sunnier place, you can't beat Pee Gee types (hydrangea paniculata). Hydrangea arborescence can make a nice hedge and can be cut to the ground
every winter, flowering on new growth. I'm sure you realize that you are trading something with evergreen leaves for something bare nekkid in winter.

I would just look around some gardens and choose what you like that matches as closely as possible your conditions. Don't believe everything they say in magazines or what the tags say at the nursery.

Our house is enclosed on the front and sides with a 7' privacy fence (top foot is lattice), but the back property line only has a 4' chainlink fence. That fence will probably remain, because the back neighbor is an avid gardener and our view is of her huge camellias and azaleas. I am about to plant star (confederate) jasmine along this fence. After I saw it used as a hedge, among other uses like shade structures, in Italy last year, it is on myy list of VERY useful plants. I do not want it on the house or the wood fence, however covering the chainlink would be a blessing.

Down here it is mostly evergreen, with some bronzing of the leaves after 20 degree weather.

I haven't had good luck with my hydrangeas, which are just specimen plants and not depended on for winter interest.