FIrst off- are you using Wy#3724? That yeast is pretty finicky and likes to stick at a gravity in the 1.020-030 range. If so, rouse it up and warm it up a little.
I personally feel that tart and/or funked saisons are true to tradition as well as being some of the tastiest beers on earth. I like Brett B. in mine, which your lambic blend should have, but if you pitch that you'll be waiting quite a while for much of anything to develop.
"I can't believe how many people think Air Lock is pronounced Hydrometer." -BigKahuna
"If you gave me a beer with placenta in it without telling me I would kick you in the nuts." -ODaniel
"We be in a big hurry for dope beer with much alcamahol and flavor, quality, balance, and aroma don't matter. We just wantz to be druck, u know?" -Yooper