The prefab would work well as the piping is already bent for your car and the kit. If you've already got a Greddy kit, why not get the FMIC that fits it?

BOV is really up to you. You can have any shop weld on a flange to your charge pipe. It's a simple install really. I though it was hard before I did it, but I look at it now and there's really nothing to it...