Well what sort of room do you have? I find that MiniZs need at least 4x3m to run, otherwise you will be better with dNanos. dNanos need a really good surface though.
RCP tracks are perfect but quite expensive if you need a big track. I think they are the best solution for a small, dining-room non permanent track, with dNanos.
I have a MiniZ track on my cellar, it is made from square foam sheets bought on a sports shop. They were originally made for creating a gym floor. Their name are "Domyos" on Decathlon shops. Maybe you have them in GB? Dunno
Some pics of my home track here :
http://www.oople.com/forums/showthread.php?t=18581