Yes, $100 should be ok. When do you think your platform will be finished?
"Finished" is a very strong word
The platform is supposed to constantly evolve according to demands of traders.
I'm working on it right now, the first thing is the web trading client, it'll be updated as development goes. Something like in a couple of days I'll finish an initial version of the web based client so that we can proceed to testing the trading engine. When the trading engine is tested and performs good enough, real BTC would be hooked up, and we are going to discuss trading API for algorithmic trading and a possibility of a desktop client.
To sum up - I will post URLs here in the nearby time, please stay tuned and testers would really be needed.