New Mattress !!!!!

Hi there, I'm not an Asthma sufferer but my partner is, we're thinking of buying a new mattress

and have been looking at a pocket sprung one but the deluxe one has lambswool and cashmere in

........I'm not convinced that this is a good idea. Has anybody any helpful information that could

be useful before we make such expensive purchase or where I could get anymore information from.