OP has said he is planning a face to face trade, and it is good security practice to only carry to such a trade the coins you are planning to sell, and not a wallet filled with extra coins. Given this, Electrum would be fine, as he can simply load up Electrum in advance with whatever he has agreed to sell. No coin control necessary.

And yeah, although a completely customizable fee setting on mobile Electrum would be better, the 1/2/5/10 sats/vbyte setting on the static slider is usually acceptable.