Gamebookers are fine.
Great software - possibly the best I've seen (although it can be slow at times).
Their payouts are on the slow side, but this is the way they work. They use a money transfer system called Moneybookers, which is used at a few other places, including Betfair.
They have a type of rebate system where, as long as you maintain a running total of 250 bets or more in the previous 6-month period, you get a 1% cash rebate on every bet you place (added to the account daily).