Please consider Stackcoin! It hasn't even been released yet, but is picking up momentum for a great launch on Feb. 22nd. It seems to be a coin developed specifically for traders and investors.
Specifications:
Algorithm: Scrypt
Max coins: around 134.4 billions
Block Time: 120 seconds
Difficulty Retarget: Kimoto's gravity well
Block Initial Reward: 1 000 000 / block
Block Decrease Rate: 15% every month
*Awesome* wallet features:
-Real time charts, up to 72 hours with configurable interval
-MA Indicator
-Real time buy/sell
-Automatic buy/sell treshold
Wallet for Linux, OSX and Windows available at launch
The developers are pretty awesome, and I've spoken to them a bit. If you're planning on releasing an API, I think the developers would be happy to incorporate direct trading with your exchange into the wallet. You can email them here:
support@stack-coin.com