We moved to South Lincolnshire almost 20 years ago from London and would not go back.
My DH still commutes to London 5 days a week for work from Peterborough station.
Stamford is a lovely place and it is near to Bourne so if you decide on the special school there it is probably covered by school transport. Look on the Lincolnshire county council website regarding school transport. www.lincolnshire.gov.uk
My DD goes to a special school which is run by C.I.T. Academies www.citacademies.co.uk if you look at their website it shows all their schools and where they are.
When my DD was in mainstream she used to have staff from St Francis in Lincoln come to her school to give ideas and support in her learning and I must say they were brilliant, they used to come to her EHCP meetings and they also supported me if I had questions, I could contact them at any time.
Do not look at Boston it has some lovely houses but it is not a good place to live, the hospital is also not brilliant, although there is a brand new special school there.
There are great villages all around and we have not regretted moving here, it is worth coming to have a look around, you will get a lot for your budget and there are some lovely bungalows around and there is always something to do.
You do have to drive and depending where you live, buses are not frequent and most do not run on a Sunday, but if you are aware of this it is a great place to live,.
Also if you like takeaways most places you cannot get delivery you have to collect, some takeaways do deliver for a fee. We do get Ocado, Waitrose, Asda, Morrisons and Tesco deliveries though.