I worked my way through college as a freelance t-shirt screen-printer, so I know this topic all too well.
First big mistake: drop the pantyhose. Your gonna need some real screen silk (actually nylon). You can make your own frames easy, but you really can’t “work around” the fabric part. Pantyhose and other such commonly available fabrics just don’t have the strength or inflexibility to serve your needs.
As for those frames, use thicker wood than you might expect (like pieces with a 2" x 2" or better cross-section). The taut screen will put the frame under tension that will distort wimpier frame members.
For the stencil, you should opt for a hand-cut job, which, I’ll admit, can be a bear if the design is complex, and requires some knack to adhere to the silk (if they haven’t improved on the old “cut the orange see-through film with an X-acto knife and adhere it to the silk with acetone” method, which has been around since, like, the 40’s).
But a photo-stencil will require all sorts of materials and equipment you don’t have, and obtaining them becomes ludicrous for a run of only 20-25 of copies. Of course you can get one made by a pro, but then they can just put in the extra ten minutes and print your shirts too.
As for ink, no, you can’t use Walmart wall paint. I used to love a brand called Versatex, made exactly for this type of project. (Don’t know if they still exist.) It was water-soluble, for easy clean-up, but became “set” on the fabric after you ironed the printed part of the shirt. Plus it was available retail in small quantities (a few fluid ounces, to a gallon.) I got mine at a good art supply store.
Bottom line: I suggest you go to an art-supply/craft/hobby store and look for an all-in-one kit. They make them for exactly your kind of needs.
(Don’t hesitate to ask if you have exact questions.)