At the end of the day, you will go with who is available in the timeline you have. I know people that swear by one shop or another, or swear at one shop or another. I lost a sale because one shop did such a thorough pre-buy (down to oil on a hose that was right below the oil filter - with no context) that it scared them off. If you worry less about the scary stories and get your hands dirty on your own plane, you can't help but be surprised how much better you will feel about whoever you choose. That being said Greg or Warren at KBJC will do a great job, they are small but very busy shops. They don't charge MSC prices and I know for a fact that one of them had four Mooney's in the shop when I went to ask about my brakes. Still, if you wait a week to decide it will take that much longer to get a pre-buy done but I would say NEVER do a pre-buy when you are no there to watch and get to know the plane.