Not sure if Turkish airlines has flights from Manchester or not but if so, check them out. I used to use them all the time flying from London to Bangkok. The average cost of a return ticket was about £389.00 including taxes. The last time I flew to Thailand was with them as well and that was nearly four years ago so prices would have gone up by now but even at that time, they were far cheaper than any other airlines and you can buy your ticket directly from their desk at the airport. Service was always good, just as good if not better than many other airlines. As I was working offshore, I never had the chance to book flights so they suited me perfectly. At that time they had daily flights apart from Thursdays. There is a short one hour stop-over in Turkey, just enough time to get a pint in before boarding.
Accomodation in HH in plentiful so simply choose something when you get here.
Getting from Bangkok to HH is a breaze - taxi direct from the airport will set you back between 2000 - 2500 baht. The are mini buses from Victory monument but as a newby in Thailand, you may find them a bit difficult to locate. The train is a great way to get down here but it takes forever. Buses also run all the time and they are for the most part, clean and comfortable.
If you do decide on a taxi, just remember to agree on a fixed price before accepting it.
Spending a night or two in Bangkok could be wonderful for you but be warned, you may end up staying longer than you expected to.
Weather wise, if my memory is correct, you should be seeing quite a bit of rain still by the time you get over but of course I may be getting all confused
Anyway, hope you have a great time here.
Don't try to impress me with your manner of dress cos a monkey himself is a monkey no less - cold fact