You might want to do an area dealer search and see who has what on their lots. You will need to know the zip-codes of the areas you want to do your search(s) in. Call them in advance to ask if you might be able to take a short test drive. Do this so you will know what to expect when you get there. Most dealers won't let you test drive one unless they feel you are a "solid" prospective buyer. I suggest you line up a potential sales person and give them your info so they will be willing to help you out when you get there. This can save you a lot of your valuable time when you arrive there.
i have done the chevy search and couldn't come up with a single dealer in the LA area witha 6 spd. the two dealers up here in my area are listed as having one each but they won't actually be on the lot for at least another week -- both are cool with a test drive, they just have to get them in!!! ugh...
Check with Power's Chevrolet in Valencia. This is just north of Glendale near Magic Mountain. I was in this past week and sale manager (Heather) said they had just received a 6 speed.