Device replacement dillema: Phone > ? > Desktop

[AyeGuy]

I have an ancient cell phone and a desktop computer. The phone has to be replaced, and I would also like to surf around the house, couch, backyard etc. (right now I'm crouched in a chair. Bad for the back to do this for long periods). I watch TV on my computer, fairly new, so it has to stay. My dillema is if I should try to replace the phone, and browse the internet, on one device, or if I should go to two: smartphone, and iPad type thing /or laptop. There are so many options out there, even for just the phone, that I am flummoxed. Any input?