As much as I like the idea, just think of how annoying that UI would be if your trying to switch a kerbals suit or select the suits for a mission in the VAB, and if you stored suits in the one part of your ship and you got your kerbal out to take them to the suit storage, only to have them die because the suit they were in didn't protect them from the conditions, then your entire mission is ruined. Not to mention having to go back and make sure all your earlier ships have the right suits on them would be a pain, so i think it would be easier for everyone if we only added evolution but not a choice of suits.