I recently had my PCM replaced and it has gone out again. This time around should I go through the dealer to get it replaced? Or does anyone know where I can get a reliable PCM that is programmed and ready to go?

 

That is very abnormal to have the PCM fail multiple times (especially if you are not messing around with it).
Replacing the PCM is not a big deal. You can get a junk yard one. Technically as I know, you should get the VIN updated in the PCM to match your car, but I have heard some people successfully swap the PCM without doing that and just doing a security relearn (which is a process of cycling the key, no special tools needed).
I would recommend looking at your current PCM for the "service number", punch that in on eBay and see if you can find one with that number from a car with that engine.

I do some limited PCM programming services. I can re-program a salvage PCM with your VIN, correct software for your car and minor tweaks if you wanted. Here's the link to my services:
https://montecarloforum.com/forum/pr...-3100-a-42773/

 

I took my car to the dealer and their telling me it's not the PCM it may be a wiring issue. I'll let you know what happens.