I would do engine and suspension first
Body kits are sort of high maintenance. I had a full kit on my 240sx and it looked good but when you wash it there were so many details. Plus ground clearance becomes an issue and everyone will want to race for no reason regardless of whether or not you instigate it.
But if your going to go outside first I would stick with TRD. I don't have a kit on my car but I would assume that a kit from Toyota would be much easier to install than one from another manufacturer. You could also try to go for a front splitter, I have seen a couple of cars that have them and they look nice.