No. Retail stores have never sold mods for Halo 2 (or any console game). Modding on original Xbox requires hardware/software exploits, not commercial products.
On Windows, Halo 2 Vista (delisted but obtainable) with the Project Cartographer client restores online play, adds mod support, custom maps, and server browser—far easier than original Xbox modding.
Only download tools from GitHub/reputable forums. Scan everything. Never run random .exe files from YouTube comments. A softmodded original Xbox is safe and reversible; a bad flash can brick it.