If you like to think big in terms of conservatory plants then you may like to consider an Oleander. Although these shrubs are generally purchased whilst still relatively small, just bear in mind that they can grow to 5-6ft or more if given the space.
I know it is sometimes difficult to find a plant that will suit a south-facing conservatory or enclosed porch but Oleanders do relish the sunshine. As an added bonus they do not require high winter temperatures so there is no need to bump up the thermostat during winter just to keep your plants happy.
Oleander, or Nerium Oleander as it is also known, bears fragrant pink or white blooms. You may also see a red flowered variety occasionally but I would describe it as more of a very dark pink.
Although Oleanders can live permanently in a south-facing conservatory, as with many house plants this is one that will benefit from a spell outdoors during summer. Keep it well watered and fed throughout spring and summer. No need to mist-spray the foliage.
In autumn bring the pot back indoors. If the weather is still good with plenty of sunny days then your Oleander may continue to flower indoors for quite a while. When all the blooms have faded, cut back the flowering stems and start to ease off with watering for the winter.
Re-pot in spring when new growth starts to appear and move into a larger pot every 2 or 3 years or when the pot becomes root-bound.
Take care when handling Oleander as the sap is poisonous. Position it well away from children and pets.
Given the space and time to develop you could well end up with a very impressive shrub that will add both colour and scent to your conservatory.