We added 42lbs of raspberry puree to a 7bbl batch and it came out just perfect. I think if you switch to Oregon Fruit you will end up wondering why you did not do it sooner.
As for adding it. I added my fruit at racking from secondary to serving. This allowed the beer moving into the tank to churn the fruit into solution. You will have some settling as the tank moves towards being empty but generally you will have an even distribution of the fruit throughout the batch so that the 1st pint and the 1700th have the same flavor, aroma and color.