Thanks for the replies - I like the quote about wearing two watches! Thats sums up my whole life
Kenpo also might not be great for self defence I suppose. I think self defence can cover many aspects though. I have done some BJJ and Judo and whilst BJJ might be good one on one its not really that practical, in my opinion, in many situations where ground fighting isnt a good idea.
In addition, Im not sure about Judo because it seems quite reliant on the gi and its difficult to throw much bigger people. I suppose whatever works though for that person in the situation they may face and all martial arts have their pros and cons.
I have heard people like Geoff Thompson (love him or hate him)argue a combination of wrestling and boxing are good in most situations.
The thing I do like about aikido is that as a smaller person (about 130 pounds/60kgs) it is possible to execute a technique on a much bigger person without needed to exert as much strength as in some other martial arts.
Anyway thanks for the replies!