frame and suspension questions

[67ss&99ss]

I am about to start taking my truck apart for a frame off resto and I have some questions.

I plan to restore the frame first, so I'm going to have it blasted, and powder coated. I guess my questions start here. I want to lower the truck, but I don't know how much. I am going to upgrade the brakes from drums to discs so dropped spindles are an option for me. I don't want it slammed on the ground, but I don't want to put a kit on it that still looks stock. I have a new set of 275/60/15s on 10" rims on all four corners that I want to keep, so I'm sure that affects my choices. What do you recommend? I know that I will have to get shocks and a trackbar to correct for the new ride height, but is there anything else? I have seen crossmembers and slip driveshafts that are made for lowered trucks too. Would this be necessary? I want to do it right while everything is apart.

I will be upgrading the engine as well, from a stock 350/turbo 350 to a LT1/4L60E. The LT1 will have a set of headers and possibly a cam, so it will be making a good bit more power than the engine in it now. Do I need to upgrade the trailing arms and/or driveshaft for the power? The driveshaft is a 2 piece design. Would a one piece be better? I've rode in trucks like this before with a built motor, lowering springs and stock suspension and they had very bad wheel hop. So, that's something I want to prevent, if I can, before the truck hits the road for the first time.

As it currently sits.