Remnantmods

Is there a piece of hardware/software that can be used to modify Xbox game properties in real time? I'm looking for some cheat engine functionality, things like changing the amount of starting ammo, number of bad guys, etc. on various Xbox games that I don't know how to mod. From playing around with emulators, I'm familiar with the practice of saving the state of all registers, then comparing subsequent snapshots of memory to find the address you're looking for, then locking that to the value you want. I thought the GameShark did exactly this, but I can't find anything for the Xbox.

Somewhere there is a huge database of trainers, for mutable games(xbox).

I have almost 3000 trainers on my xbox, does that help? lol