My advice would be to wail until you make up your mind because if you end up choosing carpet you could potentially install it on top of a concrete floor and save the cost of tile or wood. That being saaid though, it's general worth it to have some form of flooring underneath for some future point when the MRs'. inevitably decides show dosn't like the carpeting any more.I shall attempt to hoover backwards tomorrow!
I've sealed the bare concrete with a levelling sealant (No damp course on this floor after I got the asbestos tile and bitumen up) the tiles are in the garage waiting to go down... but she wants wood now. It'll be carpet next month when it's chilly outside.