Hello Paul - I am 44, have Bipolar 1, and like yourself, could not continue with work any longer as it was exacerbating my illness.
Re: benefits, it is so complicated these days for anyone claiming disability benefits. I have never had to stand in front of a board of adjudicators, but I have had to attend an ATOS medical assessment. Thankfully I was deemed to be too disabled to work and was granted Employmet and Support Allowance in the Support group, so I dont have to go to the jobcentre and try to find work. I also successfully got Disability Living Allowance (now Personal Independence Payment).
However - I only got these benefits successfully via the help of my local Benefits Options Team (part of my county council). When I filled in the forms for these benefits myself, I got precisely nowhere - and I'd previously worked in the Civil Service for 12 years, so I was very at home with form-filling!
My strongest possibly advice is that I urge you to google your local authoritys website for 'Benefits Advice' or 'Disability Benefits Options' or similar. Alternatively, if you are registered with your local Community Mental Health Team psychiatrist or psychiatric nurse, ask them for the help of a Support Worker experienced in claiming Disability Benefits. They will be able to go through all the forms and know all the best ways of explaining a mental health condition in such a way as so qualify. It all comes down to how you phrase the answers on the forms and you need an exxpert to do it for you. It is so easy to ruin your chances by a well-meaning but unfortunate description of your illness, so dont risk it!
On the matter of savings, again, the rules are complicated, but for most benefits you will not qualify at all if you have savings of more than £16,000.
Disability living allowance didnt used to be affected by savings, but I am unsure about the new PIP that replaces it - again, the best way to make sure you claim everything to which you may be entitled it to get expert help from a Benefits Options worker (NOT the staff at the Jobcentre!!! - you need people who will be on your side!) or a Support Worker who can also advise you about your wife's Carer role and the benefits she may entitled to.
Dont be put off - Give them a ring, or talk to your psychiatrist/GP/CPN to get a referral. It'll make such a difference to hand the whole complicated worry to someone else to sort it out with you! They have been wonderful with me and I could never have managed without their help. Best of Luck with it all.
Christine