Are there any minibus companies that will take us from Coventry to Newquay (and also the return journey)?

I need a 17 seater to pick up from near coventry and take us to Newquay on Friday June 24th 2011. Also to bring us back on the 26th - Drivers accommodation at nearest premier inn or travelodge can be included. cheapest cost as we are splitting it - any ideas? Can pay cash but total cost needs to be below �300 - ta.