There's an alternative to expensive or unsightly supports if your shrub roses are producing long, leggy stems you can peg them. This simply means placing a peg in the ground and tieing the ends of the stems to it so you get a curved shape. Do this in late autumn so the stems don't get blown around and broken by the winds.
Come the spring, it's a bit like having trained a climber. Lots of new, shorter stems are produced from the main stems and these flower more readily as the nutrients pass more easily along a horizintal stem than a vertical one.
I did it on my Sceptr'd Isle roses a few years ago and it was amazing. Since then I've pruned them back hard to get in and deal with a mares' tail problem but they're ready for pegging again for next year's display. They can be underplanted with spring bulbs to extend the season of interest and will flower, in my experience, from late May or early June through to early December depending on weather conditions.