Best Wallet For USDC?

Looking to transfer my stuff from coinomi to somewhere else (not an exchange)

I want a self hosted desktop app (not a mobile only app, not something that works in the browser - like i've seen tons of, metamask, etc) - and something that i can export my keys from and import to another wallet (seems coinomi had some different types of keys and importing to other wallets wasn't that easy).

i was also using atomic wallet at some point, not sure where it's at right now.

ideally looking for a cold wallet (but not a hardware one).

[update] testing myetherwallet offline version, not sure if it supports usdc, but if it does, it's what i need for cold storage