@Stephen ********
the funds of 400,000 have to be in a Thai bank account in your name only and not in your wifes. When apply for the 90 day non-o vise you can use your uk bank account as proof of funds,also they may ask for a letter of invitation from your wife (family) so it maybe a good reason to get the wife to write a letter inviting you to come and stay then take a photo for your visa requirements