Carbon on the Merge Network had a daily $1000 guaranteed with a $5.50 buyin.
Don't know if their the best but I like the Carbon skin. This may be available on
some of the other Merge skins.
I have been playing h/l for a while and due to the lack of tourneys anywhere have been forced into ring games. Unless you don't mind only playing one game a day you might consider switching too.
I agree that cash games are probably a better option. Most of the plo8 games on the merge network are micro buyins or are rebuys with small guarantees.