Modeling Market Volatility - please help

[butitsthepla]

I'm starting a side project for my job, and would appreciate some advice!

The idea is to compare my company's client trading volume (we're an online forex broker) with overall market volume/volatility patterns.. aka, if the market dries up in early summer then we should expect to see a dip in our numbers.

My problem is finding the right market indices/stats to use for comparison. I'm thinking of using the VIX and credit spreads, but those dont exactly gauge the forex market specifically.

Any ideas guys?