My favourite autumn plant fair is on this weekend - Aywiers at Lasne for anyone in Belgium - and I am intent on some top class HRT.
I'm looking for 2 or 3 shrubs to fill a 3m x 1.5m bed in full sun on all sides but shaded to the south by a 6' trellis covered in clematis in summer. It's exposed to nasty east winds in winter but I will be putting up some windbreak fabric to reduce the impact.
They need to be hardy and not evergreen as they get killed in a very hard winter. I already have several hydrangea pyracantha, hibiscus, several cornus, sambucus, weigelias, buddleia, philadelphus, deutzia, deciduous viburnum.
The soil is fertile loam over a clay subsoil and is alkaline. Usual temp range is -15C to +34C but we can get much colder - enough to kill off evergreen viburnums, eleagnus, choisya, some conifers....