[He does notice that that arm appears to have more strength than he would have initially expected. So, with that in mind...]

An iron sword may be better. If you find it is too heavy you can get a wooden one after. [Since he will still need an iron one at some point.] When choosing a style of sword you may want to think of your own fighting style. A style that focuses on speed maneuverability wouldn't pair well with a heavy weapon...likewise, a style that focuses on hard hits and stability would do better with a larger weapon.

[He smiled.] You really should find a teacher who can help you choose but if you're still undecided we can spar a little and I can give you some suggestions. If you want that is.