In the past I have always put ohlins rear shocks on my streetbikes. I am in the process of building a rvf400 and I am wondering what the best rear shock is that's available? Nitrons Race 3 way adjustable? Ohlins?

It really depends on what you are trying to achieve.

I have a Nitron R3 on my track bike which is fantastic and has plenty of adjustment.

Have you got the front end sorted also?

Everyone will have their favourite. For me Maxton units are awesome, for race use.

I have a Maxton it is great.

Going to be running newer cbr600rr forks that have been revalved for the front.