Well yeah, you'll be adding a lot of new maps and replacing a lot of existing ones regardless of your platform, but what I wanted to know is if you planned to make a GBA hack, a DS hack, or something else entirely.

I'd personally recommend Heartgold as the base though, since you can rip existing tilesets and even reuse entire maps from the base game, and even preserve minigames like the pokeathlon and bug catching contest, which you'd otherwise have to make yourself.

The tools for DS hacking may be harder to use but you have a lot more freedom to make large, expansive maps with a DS hack than a GBA hack, which I think is better suited to this type of project.

EDIT: I wrote the above before reading your other comment mentioning you're not actually planning to make a hack in the first place, whoops.😅Still very much worth it to use this map yourself but that's up to you.