I can advise you to seriously consider Blockstream's Jade hardware wallet as it has all the code clearly visible on Github and a very low cost of around $70 or so.
I'm torn between this and Trezor. I am using their blockstream green wallet software and also saw their other product which is the hardware wallet. But I think, there's more confidence in the usage of Trezor as it's the other hardware wallet that's next or now over than the Ledger hardware wallets.
While if you ask me which is the best software, my choice falls on Electrum.
Yeah, it's an open source and one of the best wallets but it's not a hardware wallet.
I really don't like Trezor and its way of storing the seed, please note that Jade does not have a secure element but it has a double PIN function that protects the seed and it can be self hosted this part as well. Also with the camera and QR system you have implemented an excellent airgapped function. Keep these things in mind, as well as the fact that if you opt for the auto compile code solution you won't have to trust any third party but yourself.