Grogan the icom hm36 mic works great with the optima mk3, you might be able to find a used one like I did, got mine for under 30 bucks shipped and it's the real deal one, made in Japan, works great, camaro1 turned me onto this setup after hearing him on air and it's been in my mobile ever since! The one from Yeticomm would probably be worth it as the owner knows that radio and I'm sure the mic they added sounds good. But for 259 shipped off the bay, that isn't a bad price for one either. I believe the one from Yeticomm would run right at 300 shipped, that's with the new mic so that isn't a bad price as long as the mic is decent. There is another icom mic that works well with it too, not sure how the hm-12 would sound but I would think it would be similar to the hm-36 as well. Both are electrec condensor mics. Just make sure to get a real icom mic if you go that route, the knock offs aren't that great IMO, the real ones are built nice and have a better element and circuit setup from the knock off I have anyhow. I also used a 2018 extreme mic with the adapter off eBay for an icom 8 pin to 4 pin cobra adapter and was told it sounded good, no echo was used though!! These are just my experiences, and as far as buying from Yeticomm and Shipping, he gets it to you pretty fast from what I have been told. Again just my experiences. I got mine off a forum member here for 265 shipped and like I said, it's a well built simple to use clean SSB radio, does okay on am but on SSB it just rocks!!