dmnf

Agree, DIY laminate floor is not easy.  Tools and time.  Better get someone to do it and it is not expensive.  I won't recommend those you always hear their ad. on the radio.  Ask around your friends.  I have used two contractors and they are good.  

If  you own the place and you plan to stay long, go for mid. range material, doesn't worth to use cheap material because the labour cost is the same.  I won't go for thicker style like 12mm.  Don't see it being too important.  If it is 2/f and high traffic, use better sound absorption under-pad.  The foam under-pad is only good for basement insulation.  Doesn't do a good job in sound proof.