Getting hubby evaluated. .. where to start?

My husband is 31 and has a few sexual issues which we think could be hurting our chances to conceive. He's always had a very low libido, sometimes has erectile issues, takes forever to cum and when he does ejaculate it's a very small amount. He started on maca root and multi vitamins with zinc last month but hasn't seen much of an improvement yet. Things seem fine on my end and we haven't been TTC for too long, so I'm gonna hold off on getting myself checked out, but he wants to get checked out by a doctor for these issues asap. My question is should he see his PCP for this, a urologist, or a fertility specialist? Any recommendations for any doctors in NYC?