how are the gun laws in your state?
i don't think he could buy them if they weren't legal to own
for home defense a rifle wouldn't be as practical (hard to conceal and keep around you, imo) so a pistol would be better
you could even get a pretty cheap .22 browning buckmark (my first gun, mostly for shooting at ranges and such) that would work fine for home defense
might be a .22 but it'll still defend you against a home intruder