I have a AOD w/ shiftkig and 3.73 gears, is it worth getting 4.10s?

Hey,
I was wondering. I have 3.73 gears and I have an AOD. I was wondering if it would be a good investment to put in 4.10s? I would like the kind of low end torque a 5speed has, so would this help? The previous owner put in the 3.73 gears, so that's why I have them. I also am planning on doing:
-AFR 165 heads
-Holly intake
-Ed Curtis cam maybe
-3000rpm Stall conv.
-manual valve body
-upgrade fuel system,
-then later on a Dart block stuff w/ 331 rotating assembly
-then a turbo

All will come as money comes (OverTime helps )

My Car:

What's a good converter then you think w/ 3.73s? I'm going to get a converter from PI, by the way