okay, for Exodia, the best to get all of the 5 cards, you need cards that allow you to go into your deck and draw more than once each turn. For example; Jar of Greed, Sangan, Card Trader, Dark World Dealings, Dark Mimic LV 1, Magician of Faith, there are others, but these help a lot. Once you have all 5 pieces in your hand, you win.
For Blue Eyes Ultimate Dragon, you don't need the dragons on your field. You can have them in your hand and play Polymerization to fuse them together. They can be on the field or in your hand, makes no difference.
There is also Fusion gate, but you Blue Eyes are put out of play and send in Blue Eyes Ultimate, so cards that allow you to bring back cards that were put of play would help if you want to use Call of the Haunted or Premature Burial. This works like Polymerization, so in your hand or on the field.
Another would be Future Fusion; however, all three Blue Eyes need to be in your deck. This allows you to take Material Monsters for Fusion from you deck and send them to the graveyard to summon a fusion monster in two more turns.
To get these cards, you can go to any hobby store that sell single cards, many carry all the exodia and blue eyes. if not, these links help http://yugioh-land.com/ and http://stop2shop.com/index.html
Good luck in your duels.