Thanks for all the replies so far.
Personally, I would like to see us keep the DR400 a bit longer and change the DR300 for a Robin alpha / 2160 2-seater - but it is not for me to buy. The club is indeed asking all its members their opinions, it will be a club decision, of which I am a member - hence the question!!
I have a feeling that we will probably get another Robin DR400, as Aerobatic Flyer says, as that will tie in with most members views. Some of the suggestions above I had not thought of and will be brought up for consideration though. The Jet A1 powered option has indeed been discussed in the bar as we had a DA40TDi demonstrator visit the club for a day over the summer.
Regards, SD..