@Andrew Cordle
I agree & disagree. If he qualifies for a FHA loan & the numbers work & he is comfortable with a risk. I think he would be crazy to use it for a SFR. I know for a fact how difficult it is to finance a 4-plex without at least 15% down in todays lending climate. 3.5% or 5% down would leave him with money he could set aside for reserves or invest in another property. If he feels comfortable investing after that, then move forward. If not, assuming the 4-plex cash flows, he can have it professionally managed while he sells it.
The fact the 95% of buyers on the market looking for a SFR doesn't seem like a bonus to me. All that means is that you are competing with first time home buyers & flippers. Unless he is lucky, the best deals will go to one of them.
If he doesn't qualify for a First time home buyers program then a SFR might be a good choice. In most areas SFR's sell for less than 4-plexs and he will have less of his cash tied up in one deal. If he decides he doesn't like it then as you said it will probably be a easy sell.