As jmcquestion said, just prime it with sugar and keg it.
Beer sitting in a keg uncarbonated is no different than beer sitting in a secondary uncarbonated. If you've got a good seal on the keg it will carbonate just fine. Worst case scenario, the priming sugar gets fermented and you're still left with a blanket of co2 over the top of the beer.
Yes, your first pint will have yeast in it...but is it really a big deal? Just pour it into a glass, dump it down the drain, and you're ready to go. The yeast will drop out of suspension once it's had some time in the keezer anyway.