i use one of these
http://www.galatent.co.uk/more_detai...ItemCode=07302
on a deal at the moment 3m x 4.5m for £180
sides are available as well as long as every spare part if you ever need to repair it after a windy meeting etc
totally waterproof roof, taped seams etc
mine has only ever gotten damaged on the windiest days & was easily & cheaply repaired
