I probably am overthinking, I do that.
Found these on Amazon...dual band, high gain, aesthetic should look alright on a white Sliger SM580:
I went with screw-on antennas on the same board.
Any antennas with an RP-SMA male fitting will work. Just make sure it's rated for both 2.4 and 5.0 Ghz.
Something like this:https://www.amazon.ca/gp/product/B07TQ4Y47D/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1