It's difficult to say which base you'd work hardest at. You tend to work more when you've got less than 500 JAR25 hours as you're cheaper to the company.
At LTN I believe FOs are getting around 60-70 hrs a month, at BRS we were getting close to 100 in Nov/Dec/Jan/Feb/Mar but it's dropped to around 75 or 80 now as more FOs have arrived. STN colleagues are getting around 70. In the summer this is likely to pick up.
Generally new bases that open offer the best way of racking up hours initially as they are often under-crewed for the first few months.
If you're floating base you're v.likely to hit the 900 hours in a year. Most other FOs I know who have a fixed base are getting around 800 to 850 a year. In my first year at RYR I flew 800, and that was split between three bases, with BRS being the busiest.