I have a 6th Ed Heisieg Deck
and a Kanji Damage Deck

Both have about 300 Kanji done but they teach different Kanji so far but SOME over lap.

Is it doing too much using two of technically the same deck?

Should I only use ONE kanji deck?

It seems as if I am doing "40" kanji a day by using both of these decks... so couldn't I just do 40 new reviews of just one deck? Seems smarter but I just need your input

Go with whichever one you like better, but I would suggest you go with Heisig instead of Kanji Damage. Kanji Damage has mistakes in it that haven't ever been fixed, and seems to have been put together without the oversight of people who are actually knowledgeable about kanji. Heisig on the other hand has gone through multiple revisions, and is really good about warning you when it's telling you something different than what you would find in a kanji dictionary.

If you want memes and stuff in your kanji learning then I'm sure the stories on this site will be more than sufficient, and you won't have to re-learn as much stuff.