What is a good PDA as laptop/tablet alternative?

So, what are some decent PDAs that can replace laptops and tablets today? I want one that is heavy, has a long battery life, thick and durable, has a screen of at least 800x600 resolutions, has modern hardware that supports all the latest stuff, has a full QWERTY keyboard, and preferably has the function using either a stylus (touchscreen) OR using navigation buttons mounted near the screen to scroll through the device. It of course needs to have the other functions as a laptop as well.

I first found out about PDAs after I played DOOM 3 which is a great game where the main character is a marine with a PDA. He runs around a big abandoned building and collects memory cards that have been strewn around the place for some reason. There are also mutated rats that occasionally appear to fight you. I thought the novel idea of a mobile personal computing device was actually well-done in the game and looked it up.

Try these.

Um, a cell phone?

I’m not sure exactly what features you’re describing. For example, do you mean a physical QWERTY keyboard, or a virtual one on the touchscreen? And what do you mean by “the other functions” of a laptop? USB ports for external devices? Internal SSD with significant storage space?

I don’t play video games and have no idea what the device in Doom 3 looks like or what it does, so I’m sort of in the dark.