URD is probably going to put out more power than the TRD blower for tha basic reason that TRD blowers are tuned a lot more conservative(warranty purposes) than other aftermarket blowers not b/c they're lesser quality.
There's a guy on the "blue" forums that's putting out around 360 to the wheels with URD s/c, CAI, exaust and I think headers but don't quote me on the headers.
SO basically you have the power vs warranty dilemma, I had the same issue when I was getting my s/c for the 'rolla XRS and I went for the greedy supercharger, for modability and power believe me the "Speed" bug is just as bad if not worse than the "wheelin'" bug
If you have any questions about supercharging your FJC I could talk your ear off. Not that I am a 4.0L guru but I do know quite a share abotu toyota(or yamaha for tht matter) high compression engines. My 'rolla compression ratio is 11.5:1 vs the FJ's 10.5:1