To be totally honest, I've never seen them in any store--not even stamping store. I'm a TAC demo and we sell them, but there are also other places online you can buy them if you do a search. I can't give you any recommendations of a specific place, though, since I've never gone through anyone but myself. Depending on what kind of red you want, you'd probably want to go with either Moulin Rouge or L'Amore Red.
Here is the manufacturer's site to read a description....
http://www.stewartsuperior.com/html/...id_inkpad.html
HTH, :-)