The National Institute of Health Research (NIHR) Research Design Service supports researchers to develop and design high quality research proposals for submission to the NIHR and other national, peer-reviewed funding competitions for applied health or social care research. This support is provided free of charge.
You can find your local RDS here: http://www.rds.nihr.ac.uk/
Information about funding for PPI at the research design stage can be found here: www.rds.nihr.ac.uk/ppi/funding-award.