That cam is a good choice for your application. It has about 16* more intake duration than your stock 5.3 cam, so you will notice a difference. Even though it has specs similar to the LS6 cams, it will not perform the same - the valve timing events are different.

The comp cam has an early intake valve closing (33* ABDC @ 0.050 lift), which means it will pretty much be done pulling by 6000 RPM. The LS6 cams close the intake about 12* later, which allows them to pull past 6000 RPM.

But the comp cam will produce more torque lower in the RPM range, which is what you want for your truck. Both cams have similar seat-to-seat overlap specs, but the comp cam values @ 0.050 lift are a little closer together, so it may have a little bit more noticeable idle than the LS6 cams.

You definitely should opt for the LS6 springs - the comp cam has higher lift and more aggressive lobes than your factory cam, but I would just reuse the locks and retainers (assuming they fit the new springs). There's not much benefit from titanium retainers if you're not reving past 6000 RPM.