Im guessing the P's will be the best for you. You don't need a phone and you can buy pierces for extra content. The color tamagotchis get more refined the newer they are and for me i think that the newer they are the more features they have. But don't let that stop you from getting an ID L or...
I dont think you're going to be able to get one for so cheap. You can check out my Ebay corner post (i found some relatively cheap ones.) The cheapest you be able to find it probably $15 without shipping...
Don't use a knife!! Be SUPER careful that you do not strip them because if you do that is going to be a nightmare. You should really just ask some friends to see what screwdrivers they have or you could buy a small set online. If you can't do either of those you can take it to a watch/jewelry...
WHen i was little it was so amazing playing tamas and now with color and different versions the old me would have SO happy/excited but Im not that into them anymore and that makes me really sad. How can i get back into them? :(
Huh thats cool. They look very accurate and i didnt even know they actually made knock of color tamas. I would buy it to try it if i had the money though.