i have about 150 plants growing at the moment and have found devon chilli very helpful and a very good company to deal with. they sell seeds, hot sauce and plants. and the best bit is they are cheap and no postage.
http://www.southdevonchillifarm.co.uk/if you are in the hampshire area near me there is a woman at the bridgemary car boot sale every sunday that sells a massive selection of chillies, tomatoes and coriander. chilli plants .70 pence and ?1.20 for the nagas
https://www.facebook.com/#!/Yvonnes.Plants?fref=ts
struggling to link that so just do a search for yvonnes plants