You have 2 issue with going to a larger duration cam with this engine for street use:
1) You have a fairly low compression ratio engine and if you put a bigger cam in it, it will drop the low RPM torque into the toilet. That is why the advice to go with a higher stall torque converter: that should be done to match a hotter cam; if you don't, the engine won't be ready with adequate torque to take off when the TC starts to lock up.
2) Your breathing with the stock heads and exhaust, is limited at the higher RPM's. So, again going with a larger duration cam will help, but it will still be somewhat choked off at high RPM's.
A milder cam like the Lunati Voodoo Cam 10200701LK will not hurt the low end torque for the street too much, and the better lift will help HP a bunch at higher RPM's. I might even go a step lower to the 100200700LK. New valve srpings should be put in with this. The idle may not have all that much attitude, but as has been said, that typically works against good low RPM performance.
And ditto.... put on a good exhaust! That will help the exhaust note.