These are called "indefinite pitch" instruments. Yes, some triangles sound at the pitch of C#, but I've noticed that a lot are tuned to sound like an A. But the truth is, they are supposed to be any particular note at all, so don't write for it to be any certain pitch. Most orchestras/bands will only have one triangle, or two if they are fussy, so don't be concerned with pitch. And again, don't treat Reason as your bible. In real life, triangles have so many higher harmonics that they sound different from depending on where you are in relation to the instrument. To write for triangle, put it anywhere on the stave. If it has it's own staff, make a one-lined percussion staff and put it on the center. If on a five-lined stave, it is sometimes put on the first ledger line above. Whatever you do, just make sure you mark it as triangle.
Snare drums are the same, as well as toms, bass drum, gong, ect. You can write for "high triangle" and "low triangle", or "high-pitched snare" and "low-pitched snare" (note that it is unusual to distinguish between low and high for these instruments in the first place), but there is no way you can get them to sound like the note you want. Again, they are all "indefinite pitch" instruments. Glockenspiel, timpani, and others, are called "definite pitch" instruments, and so they use treble or bass clef, whichever is appropriate. Indefinite pitch instruments are written on a percussion stave, which looks like either of these:

For you experts, why are there two different clefs? One I hear is "neutral clef" and the other "percussion clef". What is the difference?