I just read a review of the iFi Zen Can amp at ASR. It looks like the Zen Can performs best when driving high impedance transducers. That means you'll have to get a different amp if you want to enjoy low impedance head gear.Thanks! It does sound like they'd fit me well. My only concern is their super low impedance. My FF5s are already picking up quite a bit of hum from the amp at 45ohm. I'm guessing the 16ohm on the Yincrows would exacerbate the issue, right?
Anyway, here's a few high impedance recc's:
RY4S Black 300Ω - Don't let the low price (~$12.00) fool you. These budget buds are bang for buck high impedance earbuds that sound really good when driven properly and should be a good match for the Zen Can. Heck they are so cheap just throw them in your shopping cart, you will be surprised at the sound quality. They don't include a cable, so get some mmcx cables from their store if you don't have spares.
Puresounds PS100 600Ω and @baskingshark already suggested the Yinman 600Ω. The Yinman 600's store picture has not been updated.
This is the current version, wooden shell and stem. Standard with 3.5mmSE plug, but you can message them and request 4.4mmBal plug at no extra cost.