Option A) get a good strong stake and train the main rose stems round and round it to the top and tie them in at intervals allow the stems to grow to the length you want then prune out the tips will give a standard effect without losing vigour as you can replace the stems when they start to fail by letting a new one develop from the base
option B) choose one main stem and stake it upright prune out the rest and rub out the side buds as they develop up to the height you want then just keep the top shoots pruned to the shape you want, I find the stems on mine only flower for about three years before giving up, worth the effort as it is such a lovely plant
As it flowers so early training a late summer clematis up through it would be nice, one of the large flowered ones that you hack down every year would be best and least effort to maintain