Yes, they are the essentially the same - the Antec uses the basic Chenming chasis. The are minor differences - front plastic bezel design and the presence of an airfilter in the Antec (which the basic Chenming / Chieftec) does not have.
Personally, I wouldn't get either of them. They are good cases that are a proven design but case design has moved on now. Have a look at the Antec 3700BQE - its a better case IMO (although it comes with a PSU).
Athlon XP 3200+, TT Silent Boost (its rubbish as well as loud) Gigabyte nForce2 mobo (stable but lacks tweaking options), GF4 Ti4200 128mb, Lian-Li V2000