I have uneven skin especially around my neck and I've tried everything to get it to my normal skin tone but nothing seems to work. I am living in the UK and products that contain hydroquinone are banned here. I would like to know what happens when I buy products that contain hydroquinone internationally, basically what I'm trying to say is whether customs will withheld these products from me. Is there a possibility that I will actually get these products.

You risk a company sending you fake products that you can't do anything about.. You risk getting harmful fake chemicals that can harm you. You risk being fined for illegal possession of prescription medication if you do ever really get the real chemical.
You risk paying for it and it being taken at customs.