Hi i am just up the road from you near blackburn.
That is a busy schedule. although i can see that most of them are in groups of twos.
do be aware that at that time of year everywhere is super busy as compared to other times.
I don't know what sort of accommodation you are looking fo and I have no doubt that you will get some but be aware that a lot is booked up and some is cheaper before you get there.
Make sure that ko phangan does not coincide with full moon or new year or you will not get any where unless you book 3 nights.
Been to Bangkok., phi phi, Koh Lanta, samui and loved them all you have a good mix there to give you everything that you are looking for.
Enjoy and post a report when you return.
Don't blame you for being excited !

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Kiss
God laughs at people who make plans.