Help, im new to golf?

I'm confused. Are you wanting to get him a replacement for his Mizuno MP-58 6 or 9 iron? Did he lose whichever one or do some irreparable damage to it? Or do you want to get him a set of Mizuno MP-58 irons(3-pw). Is this a set that he has expressed interest in wanting to get? It would be kind of strange to buy someone a single iron unless they've broken the one they had. What is it you're wanting to do? Individual irons aren't difficult to replace. You can go to the pro shop and order one. You're talking in the neighborhood of 80-90 bucks. The clubs have numbers because they are made to be hit specific distances due to the loft of the club. I would like to help, but am not sure what you're looking for.