Easy one first: choose your impression and check out the 'where to buy kit' threads and also the fit guides found on the drop down menus at the top of every page of the forum.
Now then by 'kit' you mean an airsoft gun? To be sold anything that looks like a gun in the UK you must be over 18. Secondly you must have a legitimate reason to buy such a thing and the UKARA registration (not really a licence) is the easiest route to go. You must be a member of a valid airsoft site (one with public liability insurance and takes part in the UKARA scheme) and played three games in not less than two months. Then you can apply for UKARA.
Edir: This isn't the only way to buy an airsoft gun but for simplicity and since you asked about UKARA a simple answer is given....
The other option is, as C-W says, decide on what you want to be and get the uniform and webbing etc. first. Then as well as joining a site, buy a garishly painted but otherwise std airsoft gun from someone like Airsoft Scotland. These are not classed as a RIF so anyone can own them and when you get your UKARA membership sorted, it's a 2 min job to re-spray them in a more realistic colour.
Best way i believe, would be to rent gear from your local site....get enough "stamps" to send off for your UKARA license then.
By that time you should have got a good idea of what you like....then spend the cash on getting the AEG. Talk to people at the site, they'll always recommend items.
That way you miss out having to own a bright green/blue AEG.
