Well, it kind of depends on whether your old laptop was a doddery Windows Vista with just enough RAM to run PowerPoint, or a power-consuming monster that could run anything on ultra with no problems what so ever. Because at the end of the day, if your going to get a high-spec custom built laptop with a $1000 budget. Then a few old 'clip-on fans' would be great if you were deciding to keep it intact for less than 5 minutes .
Unfortunately there isn't lots in the way of accessibility when it comes to building laptops. Not to mention. as soon as you get even close to what a gaming Desktop PC can do with a $1000 budget, your probably looking at twice the price! I built my PC with way over £1000 budget and it still doesn't come out to be a flawless when it comes to games (don't get me wrong, it's still bloody amazing!).
So with that in mind, I would first advise you to get a Gaming PC and not a Gaming Laptop just for the fact you would get far more value for money over there . It would also depend on what games your playing, if your just playing minecraft and other low intensive games then ignore everything I just said, however when someone says 'gaming laptops/PCs', it usually means optimized for everything you can possibly throw at it.
Finally, I wish you all the best with your hunt for the right Gaming PC/Gaming Laptop. It took me nearly 4-5 months before I was completely happy with what I wanted so the moral of the story is, if you find an absolute jaw-dropper of a deal. Chances are, there's gonna be a better one right next to it .