Right....after scouring the Internet, posting on various fora I think I have the solution to my buggy conundrum....

An ABC single with two extra seats to make into a double or triple and the stability kit (ie: 4 wheels).

Does anyone have one of these?
Would you recommend it?
What is the difference between the two types of extra seat?
Can you divulge what you paid for it?

Thank you kindly....