If I got a platinum, the first mod I would do is finding a new tailgate w/out the aluminum thing across the back ...
on a more serious note ... I would add at least 35% tint to the front windows, if not 20% to match the factory tint. I would add a tool box to the bed (which I have) ... but seems MOST around here prefer some kind of bed cover.
Also, since you're looking at a toneau cover, then you should consider a rubber bed mat in lieu of the bed liner (if you don't really beat the hell out of your bed) ... Here's a link to one:
I know DeeZee makes one too for about half the price, but not sure about fit/finish/quality.