Can anyone recommend were I can buy and get a JVC/Kenwood head unit fitted in Bangkok or Pattaya. Thanks.

You could try Boy Sound in Pattaya. Recent post here and any search will bring up loads more.

http://www.thaivisa.com/forum/topic/557747-if-you-need-anything-for-you-car-boy-air-and-sound/

I do not know if they specifically have what you want but they can probably get it.