Hmmm... better start off with the EX Delta Species Steeplechase (sp) Deck. You can modify how it works or the card to be added and removed later on, but this is what has been recommended by a lot of people who also play the TCGs with me.
To be honest...if you really want to stick with one of them, go for the Team Rocket Returns deck, but I'd get Shadowquake (EX Legend Maker). It's definitely one of the best decks I've ever used.
The only thing about Steeplechase is, IMHO, there's too many Fire Pokémon. Not the best idea to make a solo-type deck. The Crobat deck is better; more leeway when editing some of the cards in it.
in my opinion, if you could, you should get a team rocket returns jessie deck. it has good strong pokemon, but i advise switching out the 3 hoppips and 1 skiploom for something else. if anyone wants ill post a list of cards in the deck.