Novice laminate questions

Thanks for letting me join this forum!

My living room is 12ft 6 by 13ft 6. How many square meters of laminate flooring should I buy?

The floor currently has a carpet with an underlay. Can I use this underlay for under the laminate or must the laminate have a special new underlay and if so, which brand is good?

What are the best brands of laminate flooring? I have just seen Egger for £7.65 and Balterio for £14.49. I don't want to buy something rubbishy that is going to fall apart in a year, but then again I don't have money to waste.

Is it better to employ a carpet shop to supply and fit, or buy the materials myself and then employ someone to fit it?

There is laminate flooring in another room, and the beading is peeling and dented, and appears to be made of MDF. Clearly, this is not hardwearing enough for beading. What should I buy as beading for the new floor (and to replace the beading on the older floor?) Should I just buy something from B&Q or is there a special kind of beading for use with laminate flooring?

Thank you in advance.

The area is 3.81m x 4.1m = 15.621 square metres.

I guess you should buy a bit more than that though. Sorry, but I can only help with the maths and not your other questions.

Welcome
You will need the underlay designed for laminate, there are 2 types I think.