Linux Flavour and Scaling

I have about 6000 servers, each running NETSNMP that I wish to poll, and write poll results to the MYSQL db, no thresholding, just data collection. What is the best flavour of Linux to use ? I prefer SUSE but REdhat is ok too. I want the least missing libraries, install problems, etc. In fact I'd like to know what Linux the product is developed on. Also how many Linux boxes would I need to poll 6000 servers on a 10-15 minute polling interval (cpu, mem , disk, interface). My needs for OpManager are pretty simple, but it needs to be capable. Can two different OpManager boxes doing 3000 servers each write to the same MySQL db into the same tables ?

Thanks !

I hope to become an OpManager customer.