The pins and drill bits are nothing special. Any similar sized pokers will work. The drill bits aren't needed as much, they are just for when the crap builds up in the nozzle to heavy for the pins to be able to easily get out, though with enough work the pins will still be able to get the crap out. So the drill bits aren't absolutely necessary. Its up to you if you want to order the official ones or not. I did because I wasn't sure when I first got my FR-300, but since I've been using other similar sized drill bits for the few occasions I've needed them.
I have 3 of the original pins, 0.8mm, 1.0mm and 1.6mm. They measure 0.72mm, 0.91mm and 1.40mm respectively. Though absolute size isn't really that important, as long as the pin is slightly narrower than the nozzle you want to clean with it, thats all that really matters.
For the original drill bits, I had gotten the 1.0mm and 1.6mm bits. They measure 1.0mm and 1.5mm respectively. For replacements I've been using a 0.95mm and 1.45mm drill bits that I had laying around (not sure what the label on them is, probably supposed to be 1.0 and 1.5, but not readable) with no issues. Again, as long as they fit through the hole, they should work fine and aren't really worth worrying about.