What's his history? Is this his first cycle? If so than I would keep it simple and low dose. There's no point in overdoing it his first time out. Since he is a boxer in training, his exercise level should already be good. Tell him to go on a high protein (200 g/day) moderate carb, low fat diet and stick to something like fina at 50 mg ED. Maybe if he turns out to be prone to fina dick add a little test prop in as well, say 50 mg ED. Eight weeks of that (diet and training plus the fina/test prop) and I think he'll have no problems adding 15 lbs of solid lean mass. Also, both fina and test prop are short acting and out of the system fast (in case of testing).
-Spidey
edit: I see a few people suggesting halotest. IMO, that would not be a good choice. Halo has relatively low anabolic effect and is quite toxic to boot.