Most LO's transition to 1 nap between 12-18 mths of age so it's very likely that he's ready to handle 1 nap.
I would maybe aim for a nap around midday if you can, just to allow him to adjust to the longer A-time in the morning & not to get OT. Once he has adjusted then you can start to push the nap a bit later if needs be. It can take a few days for LO's to adjust to 1 nap so if his naps are shorter to start with, stick with the same nap time for a few days & they should start to lengthen (also do an earlier BT if he short naps).
You can alternate 1 & 2 nap days, I know a lot of Mums who have done this whilst doing the 2:1 transition, I guess it's what works best for you & your LO!