I'd go to a good 'n busy parachute centre where they pack all the time.
www.bpa.co.uk will give you a few addresses.
As far as technique, well I have 1500 jumps in everything from Skyvans to Tiger Moths (an interesting low speed experience by the way...). Only one aircraft emergency though and that was out of a 206. By the time I had "thrown" my four static line students out the door we were a tad low which left just enough time for my patented escape procedure. Aim for a hole in the aeroplane, jump through it and pull something...quick.