Anyone know of a good Pontiac Mechanic?

[OhBuoy]

Here is the situation:

I have a 2001 Pontiac Grand Prix GTP with 54,000 miles on it. Car was running great. For about a month, we knew one of our two cars had to be leaking antifreeze because you would occasionally smell it by where we parked the cars. There was no evidence of a leak on either of the two cars. Eventually, I noticed a small puff of steam comming from under the hood on the Grand Prix. Took it to the shop and they identified it as a lower intake manifold leak, which is apparently common on these cars. They replaced the intake gasket and on the first long drive afterwards, I noticed that when I would decelerate, the boost indicator would come on and then the coolant level light came on. I took it to them and they stated that there was an air pocked causing the coolant light, and they could not replicate the boost indicator. The next long drive left me stranded and they sent a tow truck. This was supposedly due to a loose vacuum hose. Since then, the car has been in the shop 8 times for one or a combination of the following symptoms:

1) Boost light comming on with deceleration.
2) Stalls when comming to a stop and will not restart.
3) RPMs get stuck at 2500+ RPM, car will pull you up a hill with your foot off the gas at 45MPH.

Symptom 1 and 2 typically kick in after observing #1

The MAS, TPS, fuel filter, plugs and wires have all been replaced (was not charged for fuel filter, plugs and wires). The last time it stalled, I had them tow me to the dealer. Dealer identified that the O2 sensor was bad and replaced that. I told them that I was skeptical that was the cause, and sure enough, I took the car out and was able to duplicate the boost indicator comming on with deceleration. They brough the car back into the shop and are saying that it needs a new PCM for the tune of $1100. They cannot guarantee that this will fix the problem, and since it is an electronic item and needs to be flashed, there is no way they will take it back on return if it turns out that it is not the problem. Also, they are hedging themselves by saying that additional sensors could come up as bad that were not being reported before.

Now, the car is throwing an EVAP code. The gas cap is on tight and I have removed and reinstalled.

Right now, I am torn. I have considered replacing the car (a shiney RAM had my name on it), but will be potentially unemployed come October 31st. I have about $1800 in repairs thrown into it with the intake leak and the following repairs. We have been getting by with technically one vehicle because I am afraid that I will get stranded again, but this is taking a toll.

I hate to sound like the typical "it worked before", but the care truly ran fine. Heck, I could understand some things that are old breaking while they were fixing it and having to replace (and pay for) those (vacuum hoses for instance). Research has indicated that this is likely a vacuum leak or something electrical. I would like to find someone that could give it a third set of eyes (fourth if you count mine) and give me a better feel. Ideally someone that might be willing to try a used computer if they really think this is the issue. But with the EVAP, I am really thinking that it is vacuum, but have yet to find anything.