You can buy it off GOG or Steam. If you get it from Steam, it costs $20 when not on sale, but you get the first seven games in the series. You can also buy only King's Quest 4, 5, and 6 from GOG.com for $10, and GOG does a good job of making these older games compatible with modern systems by prepackaging them with DOSBox or ScummVM.
If you are getting the games through GOG, you need to install them first (which may require Windows). If you don't have Windows, try one of these (1, 2) extractors.
(I tried it: Wow, GOG has updated all the games from DOSBox to ScummVM since I last looked, even KQ7. I'm not sure I'm a big fan of this; in particular giving KQ1--3 a mouse cursor which they didn't originally have.)
If you open the game folder, you can safely delete the "scummvm" folder, as well as any files starting with "gog", "unins", ".ico" files, ".pdf" files, shortcuts, etc. Copy all the remaining files to your phone. Then if you run ScummVM on your phone, you should be able to point it at the directory containing the game files and it will pick up the game.
(I'm trying it now; I'll update this if I discover any other steps.)
Your laptop should be able to handle at least most of the King's Quest games without any problems. I can play at least up through KQ6 using an emulator on my android phone (see https://play.google.com/store/apps/details?id=org.scummvm.scummvm). I don't think the emulator supports the later KQ7 and KQ8 games. I suspect my phone could run them though if the emulator worked.
You can get them on amazon and they seem to be a decent read from the reviews. Though I do think they are probably being reviewed by people that are hardcore into the series so I would take all the 5 star ratings with a grain of salt.