To get rid of the CEL you can just disconnect the battery for 10-15min and that will clear the code. I just did the same thing last week. I had my intake manifold off and forgot to plug in the TB when I was finished. Mine was a little pissed off until I cleared the code.
The block fitting is 12mm x 1.75. Your oil pressure sensor is likely 1/8" NPT. You could use Auto Meter 2278 to convert over the block. You can stick the engine oil pressure sensor in the back of the head. I THINK it's about 10psi lower pressure there but it is enough to keep the idiot light happy.