If you get in touch with your local jobcentre plus office they have dedicated officers called Disability Employment Advisers who work specifically with disabled jobseekers. They may be able to point you in the right direction with regards to either retraining and/or a way to get payment for training you've identified yourself. The criteria seems to be job viability, if the training you want directly links with a possible job vacancy ie. you will not need to claim benefits and will be independant of the state then they may be able to make a business case to get funding for your training. The local JCP office will be in the thomson local.