Hi Hayzees
I'm on the 4pm flight from Bristol when I go next month too

it lands at 10.10pm local time so I am expecting to be at my apartment around midnight (that's with private transfer).
Dalaman airport isn't normally too bad at that time of night so hopefully we'll make a quick exit - if there are any hold-ups it's normally the visa queue...
Some mini-markets will be open when you get there (quite a few are 24 hour).
Steve's right, if you prefer a named brandy, best to buy at Bristol airport or on arrival at Dalaman - I remember last summer there were some good offers on spirits at Bristol. But if, like me, you're not fussy about brand you can pick up the "local" stuff quite cheaply - certainly ok if you're going to add a flavoured mixer (like coke/lemonade) - you probably won't even notice the difference after 2 or 3!
Mazz