Alto sax and tenor trombone should go well - they feature on Mark Nightingale Quintet "Out of the Box" CD - tenor trombone is equivalent range to a baritone sax. I am less sure of Alto sax with Trumpet/Flugel horn - different textures but same range. Other than that alto sax, tenor sax and trumpet/cornet would work well - lots of videos as you might imagine as it is a classic combo in sextet. Also alto/trumpet/trombone ,the trombone needed to provide something deeper.
Kind regards
Tom