You know, I've always disliked d4s and the special way you have to "roll" them for a fair result. Too much technique. A successful roll you can see and even make rules about, as in craps (must hit the back edge of the rolling surface to be fair). I've never had luck finding what I want (which is just a d8 with two surfaces marked with each number 1-4).

I feel the same about some weird d3 shape too, because it doesn't really roll and would require a similar "toss" that's hard to judge. I'd rather have double-marked d6s, which do seem to be available.