What you should do is to make a list of everything that you're going to need. Source your parts, get a general idea of how much you need to spend, and start saving your money. The best thing you can do for yourself is to save up and buy all your parts at once, or at least buy everything you'll need from a certain supplier all at once - You'll save a load on shipping, and probably be eligible for a good discount. You'll also save time, because you won't be taking your truck apart, upgrading a single component, and then putting it back together, only to repeat the process in a month.