Inexperienced first-timer looking for guidance on starting a hack

[jedicms]

I'm not sure which game to use as a base, but I'd like to create a Pokemon Gen 1 hack.  I have NO programming/coding experience, save for one C++ class in college, but that's an overstatement.  I'm already using a base hack of Red that skins the sprites from Gold/Silver and some additional work.  I want a version that includes the animated Pokemon sprites from Crystal, colored maps/routes of Kanto from Gold/Silver, Gen II evos of Gen I creatures, more evolution items, altered pokemon typing for certain pokemon, added moves to learnsets, among other things.

Knowing this, is it more reasonable to start with HG/SS that has a cleaned up battle system and reduce it down, stripping the features I want until I reach a Gen II-like experience?  I want to avoid having to fix the bugs of the earlier battle system.  Or do I start with Crystal since it is the closest I'm trying to emulate, and recreate red/blue from scratch?  Where do I start with something as ambitious as this?  I don't understand all of the files of the disassembled rom, the base-patch-hack I've already began to mess around with, or the tools needing for editing, or how the code works.

Additionally, I've thought it could be even more fun to hack PLA to do a remake of Gen 1 with the PLA playstyle, but I know that would involve a heckton more work.  If I'm wrong, tell me so I don't waste any time on the wrong one.

Thanks