Building a Gaming Laptop

Hello everyone. I'm thinking about building a gaming laptop so that I can give my desktop to my folks. I need help, firstly picking parts. I only know about desktop parts, so choosing what I need to run games is a pain. My desktop has an intel i5 and an nVidia 550 (the cheaper version I want to say) and it runs any game I throw at it just fine. Wanna say it's 8gb of memory but it might be 16.
So, can anyone help me figure the equivalents of these parts for laptops, something cheap but can still run whatever, just maybe not at max settings. The screen size of my current laptop is 14.1 inches and it's perfectly fine for me, but I'm not sure weather enough that's enough room for all the components in a gaming laptop. Any recommendations are greatly appreciated. I plan on getting a cheap barebone and filling it with the good stuff.

And btw, I built my desktop for around $500. That's why I'd like to be able to build the laptop. No point in spending $1500 on one when I already have a desktop for gaming and a basic laptop for everything else.