96' 15hp merc Water Pump rebuild?

[Wee Hooker]

So, soem 20 years ago I accomplished a couple fo water pump impeler replacements on various outboards. (i.e it's been a while and my menory dosn't work like it used to). I want to replace the (origional) impeller in my 96' 15 hp two stroke and am wonderign what I need. Do I buy just the impeller only? Do I need additional gaskets? a whole rebuild kit?

Also, Looked here on iboats and all i see is parts for teh 9.8 called out not teh 15. I'm guessing they are the same but...