I haven't ran into many contrast stitch tees during my searches but here are 2 you may want to try out;
Hanes Beefy™ 5.5 oz Ringspun Cotton Contrast Stitch T-shirt
or
District Threads - Tick Stitch Tees
Hanes Beefy™ 5.5 oz Ringspun Cotton Contrast Stitch T-shirt
or
District Threads - Tick Stitch Tees