If you buy a topit I recommend Jay Scott Berry's, also you may want to pick up some sleeve pockets.
Something that I did was use the template to make a topit for my denim jacket. That way I have an out in normalish clothes. Something else that I have done in the past is use a button up shirt.
Simply get a button up shirt, put it on pick a button that is near the waist or at mid waist (at or near your belly button. De thread said button and use fabric glue to glue the button on the hole side of the shirt. You are basically done, another pro tip taken from I think Jay Scott or someone is to glue a pipe cleaner on the inside part of the shirt, that way you can create a big or small flap that stays open.
Thats it, tuck in the shirt button it up and your good to go, vanish rings and small objects. Just make sure you have a way to make them reappear