From the UK why not use a money transfer company such as Key Currency, very safe and they ask you if you agree with the exchange rate before they send it or you can wait until it's more favourable.
If I was you I would get myself home as soon as possible and resign myself to never traveling anywhere again unless it's in walking distance and the vibrations of your foot steps don't harm you.
You're welcome, that's how we have done it and we are both 'Farangs' I did the retirement visa myself which is fairly easy and I used TLC ( the learning center) for my wife's Ed Visa
You would both have to have separate bank accounts with your own funds for you both to get retirement visas, alternatively you can apply for the retirement visa and your wife does an ED Visa (Education) and once you have your retirement visa she can follow you, but first you have to have 3 months non O and then apply for the retirement Visa, your funds need to be in a Thai bank for at least 2 months before you apply.
They speak English at immigration you can do it yourself it's easy if you don't panic and take your time, an agent should be no more than 20k if you feel you really need to use one, There is an office below The Language Centre (TLC) On Phetkasem road that can help you, ask for Apple