There are some sites out there that play Chess variants. However, Chess.com doesn't like us to advertise other sites in their forums, so you'll have to do a google search. I don't know of any that play those particular variants. I think Bughouse, Crazy House, and Fisher Random (aka Chess960, played here) are more common.
Some of the chess sites with forums have forum games going on. For example, here you can post board diagrams, so you post your move and a diagram of the position, and the other guy then posts his move and a diagram. You can also handle games that can't be shown with standard board diagrams using images. Check out the *Results May Vary group for some examples.
Years ago I read a book called Faery Chess which looked at a number of chess variants like..
Do you know of any sites which play these type of variants?