Hi Fed Up,
Having worked with BIG4 until 1 and half year and doing contracting since then I am exactly in the same situation as you are. Perhaps I am one step ahead of you considering I was so fed up with my current contract that I asked to terminate it early.
When I resigned from my £500 a day contract job I was having the exactly same thinking i.e. working as little as possible for as much money as possible and would settle for £60-70K for a job which can give me job satisfaction, a job I can love, a job which will give me work/life balance. I am in job market since last 1 month and things are not sounding very promising. I do have savings which will take care of me and family until end of the year. It was the gamble which I took however, I am hoping the decision will turn out in my favor.
Just 1 thing you need to be aware of a person earning £60-£70K outside consulting can not have a work/life balance job considering people who are earning £70K in industry are playing senior management roles and have f****ing high responsibilties which won't let you sleep anyways.
I think the best bet would be getting into contract jobs. Any £400 a day contract can give you work/life balance. On this rate if you only work 12 days per month ( on an average and factoring the period when you will be looking for contract) you will still be making ~£60K.
If you can't get £400 a day you may want to go for £350 a day and work for bit more days i.e. 15 day a month to make up your £60K annual salary. And in contracting if you use your company your 60K will be equal to 72K!!
I will watch this space for others views!!