Hi. I really hate to be a downer, but as a US archaeologist who moved here I feel that I have a responsibility to let you know how the situation really is here. Yes, archaeologists are needed in the UK - they always are. Usually because it is on the low-rung of the pay ladder and everyone tends to move away from it. Also, if you do not have a car or are willing/able to get one (or live really close to the company's headquarters), you will not even be considered. A friend of mine worked in both the lab and HR of a major company down south and she gave me a lot of information. First on her list was location and vehicle - if you say you have a car, your resume will go to the top of the list and if you do not list that you have a valid UK driver's license, your resume will be tossed out.
Second is be aware that while there are a lot of jobs - there are A TON of archaeologists trying to get work. Its a popular degree here so there are a major number of archaeologists here that can't get work. (I currently am not pursuing it because I am injured.) More importantly, if you do not already have a visa that allows you to work, you will not be hired from abroad. Companies have to pay for the license to sponsor visas - archaeology companies do not have the extra money to do that and I doubt would even if they did. No. archaeological company will sponsor a visa unless its something that no one has in the UK. Which right now is zooarchaeology. Apparently there is nobody here that specializes in zooarchaeology. If that is your specializing, then I say go for it. Otherwise, if your goal is to move to the UK, I would advise you find a different route. Again, I'm sorry to be a downer but I have personally had to deal with all of the problems of trying to be an archaeologist that I feel obligated to warn you. If you have any other questions, feel free to personal message me.