I was reading another forum and someone said that you were able to unlink the RAM from the fsb is this true?
No. Increase or decrease the fsb and the RAM moves with it. All components run on the system's BUS and are interlinked through it.
i need a ram latency for a 413 fsb and 1:1 ratio
RAM latency has nothing to do with data transfer rates. Basically multiply your fsb (quad pumped) by 4. Then set your RAM speed to half that (double data rate). That match should give you 1:1 ratio CPU/RAM.
is there a limit to which my RAM can go
Yes. Read the specifications from the manufacturer. Speed, timings and voltage required should be available from the Mfg.