Both would be suitable, plastic is lighter for moving them around or on a balcony or roof garden. Ceramic often looks better. The main thing is to make sure that they are as large as possible and quite deep as roses have deep roots. Use a John Innes No3 compost and feed regularly throught the growing season. Put a few Crocuses or other small bulbs around the edges of the pots at planting time for a bit of spring interest.