Replacing Storage Heaters with Gas Central Heating

Does anyone know what it would take to replace a heating system in a house that is currently storage heaters with a Gas system?

Outside of geting a boiler,rads,valves,fittings,cylinders,digging up floors etc etc it will depend on the size and construction of your home

There is Gas available but for some reason they fitted storage heaters throughout.

Gas may not have been available at the time of construction or storage heating was more financially viable for the builder

Is it something any plumber can do or is it a specialized skill?

Yes any decent plumber should be able to install a heating system.However you are interested in a gas heating system so you will need an RGI plumber you can find one here http://www.rgii.ie/

could i sell these heaters on to recoup whatever we may have to spend?

You could but I doubt there is a market for second hand storage heaters