Hornady sells their .365" XTP HP as a separate component for reloading. The catalog number for it is #36500.
MidwayUSA has it as well as a Speer TMJ and a Meister cast lead available too.
I'm pretty sure that Graf & Son's, Natchez, or MidSouth Shooters Supply would also carry a .364/.365 bullet or two.
Berry's also has a plated lead round nose for the 9x18 too.
I know a few years back Speer used to offer a .364" Gold Dot HP as a component but it seems that it's been discontinued.
Don't use a .355" bullet when reloading the 9x18. Because of the diameter difference, a resized Mak case won't hold a .355 bullet tight enough to make reliable ammo...bullets may slip forward and jam up your pistol or slip farther into the case and cause high pressures when fired. Besides, accuracy will be poor too.