Advice on which mattress?

HiI am looking for a new double mattress and I am so pleased at finding your website after a very disappointing visit to Benson for Beds, very limited choice and the only one I sort of liked was an igel mattress.I am hoping that you can recommend one of yours. I am 9 stone and my partner is 12.7, I can get quite warm in the night, currently have a mattress that is probably 20 years old! So not sure if prefer firm or medium I think I'm erring on the side of firm.I was looking at your Origins Pocket 1500, would this be suitable maybe with the firm option? The mattress will be going on a slatted baseAny advice would be most appreciated, thank youHelen