I good sewing machine is all you need for that. Screen print the patches and sew them on.
If the blanks already have the adhesive on the back, I would look at dye sub or screen print.I own a school uniform business and we have always screen printed the logos on the polos. I have a new school that wants there logo as a iron on embroidery patch. The patches already have the adhesive on the back. What machine would you recommend adhering the patch to the shirt? I'm thinking that other schools will want to switch in the future so I will need a machine that can handle 1000-2000 shirts/year. Thanks for all input!