to answer a few more of the questions you asked - almost all bicycle chain has links that are a half-inch long. this is called "pitch." some very old gear is "inch-pitch," and for a hot minute in the (i think) 80s, shimano made dura-ace "10-pitch" - instead of a half inch, the links were 10mm long. however: if there were a chain with smaller removable units, it wouldn't fit on your cog and chainring. it's all made for half-inch pitch chains.

also, it never hurts to measure your chainline, to be right. that phil wood hub will put the cog at 43mm from the bike's centerline. use a ruler to measure from the center of the seattube to the center of the chainring. it should also measure 43mm. if not, you might want to consider moving the chainring, or getting a bottom bracket with a longer or shorter (as needed) spindle [if you need to move your chain 2mm outward, you'd need a spindle that's 4mm outward].

that trusty trek ought to make a lovely conversion.