junkyarding soon, need engine codes

[Project84]

I'm looking for a junkyard engine swap... hoping to find a VX w/ engine still assembled, I know I'm flying a kite here, but I can hope right? First gonna find an engine, disassemble, freshen it up, resassemble, then search for a hatchback w/o engine/trans.

What engine codes should I look for? I know the VX is D15Z1 and the stamp will be visible from the front of the block w/ hood popped, and also vtec-e on the valve cover... but what about the hx engine? What is that engine code? Can someone list engine codes from BEST to WORST, please only give 3 codes as I'm unwilling to get a standard LX engine or something, I want to build a MPG machine.

Also, where do you locate transmission codes, and how do I tell if I've found an HF trans in a CRX? What is the next to best transmission in the civics and where is the code stamped? What year transmissions are compatible w/ what year engines w/ little to no modification? I don't want to get in over my head, just looking for things that will swap together.

Thanks!