Keep the old truck, leave it alone, use it for daily, and pick up a RC SRT-10 to modify. I think that's your best course of action. Ask any person who has or has tried to modify a non-standard vehicle for the sake of being "the only one" and the theme is always exactly the same: assloads of $$$$$$$$$, time, and headaches. For a SRT-10, it's probably worth it, for a old 2500 V-10 truck, probably not. Almost everything you're going to have to do to modify it is going to require custom fab, guess work, and money. I'm usually the last person to tell someone to squash a dream, but I'm also very realistic. There are plenty of RC 10's floating around for cheap that even bone stock are going to be a ton of fun, I think if you are as financially stable as you say, then go that route and I think you will be much happier.
Also, at the end of the day, no matter what a person tells themselves, when we modify our vehicles we aren't just doing it for ourself, we are doing it for attention from others. Very few people on the street day to day are going to appreciate the work you'll do on the old truck and even on here, the "newness" of the mods will wear off. A modified SRT-10 is going to get you the attention you want plus the self-satisfaction. The old truck just isn't. Leave it alone and keep for the memory and drive daily and mod the crap out of a SRT-10.