When I was looking I found that RS only stock the lower bin Ostars, however I did find a source for the higher bins but it is still a lottery as to what they ship. Typically they claim that all of their Ostars are capable of 900 lumens.
Until Osram improve their process to provide consistant tint and lumen LED's I have lost the temptation to play with them. £40 for an LED buys a lot of WA01185 bulbs.