Looks like I'm in luck!
The K series are extremely modular engines, and were used in tons of different applications. Parts from different generations are all cross compatible. Oil pumps or cylinder heads from a 2002 bolt onto 2015 engines, and vise verse. And, it appears the EGR system is *probably* the same way.
Here's the water pump assembly from the Accord, which has EGR:
Here's the TSX, which my engine is out of:
The TSX even has the EGR chamber, stamped "RAA" same as the Accord:
Incidentally, the EGR valve used is identical to the one on the Insight.
So, it looks like I'm going to get a water pump housing from the 2.0L RSX Type S for the oil warmer, the water outlet passage from an Accord 2.4L, and both should bolt onto and work with my TSX.