BCH is coin forked from the Bitcoin blockchain. I have some purchased on an exchange called Kraken which you will have to verify yourself on.
Let me explain in sum.
You could have/can obtain(ed) BCH in 2 seperate ways.
1) By owning BTC before Aug 1 (fork day). This would allow you to split your Bitcoin, thus mean if you owned say 1 BTC beforehand, you will have 1 BCH as well.
2) The second way is to deposit another currency (I used LTC) into an exchange and buy it that way. (People who had BTC in an exchange had their BCH split for them, and these are the ones in which you are buying).
This leads to complications though as BCH cannot enter or exit an exchange as for technical safety reasons. The only BCH existent in exchanged in the moment are ones forked from users holding BTC within them.
This leaves us many coins outsides the exchanges unable to get in, and as for me I can't get mine out. For them to deem the technical risks lowered will take several days.
Make of this whatever you wish, but I see a great future, I mean, people will eventually treat this like BTC.
Answering another question: Im sure separate wallet software is in development at the moment. (So people can split their coins)