With Marik's SylvanRa-Farm-Deck it is realy easy to farm coins in the Blue-Eyes-Cup. Lost only once against Rainbow-Neos.
It is not necessary to farm lvl40, you make enough DP with lvl20.
It is not realy necessary to get Ra fast. If it's good then but otherwise it's not bad either. With the Sylvans and Mokuba's Dragons you can keep your opponent small and when you draw Ra (and perhaps an additional spellcard) you can finish it.