One pokemon team challenge??

[Hawky]

I've recently heard of a challenge, almost like a nuzlocke, but the difference is instead of catching only one pokemon in each place, you have to catch the first pokemon you encounter, box your starter, and build a team consisting of only that one type of pokemon you encountered first. So say I choose a starter, I go out, and I encounter a pidgey. Well my team now can only be six of them, and I have to complete the entire game like that. Can't have any gift pokemon in my team. Potions and such may be used, and if a pokemon faints, it's dead, but you again can only catch another pidgey.

I heard of someone who completed this challenge, and referred to it as the joey challenge, because his pokemon were only ratattas.

Some versions say you can evolve the pokemon, as long as they all started out the same, and some say you can't, and have to stick with it's first evolution.

Of all the pokemon that can be found in the first area of any pokemon game, which would you prefer to do this challenge with, and why?

I've thought about this myself, and haven't come to a conclusion yet. But let me hear your thoughts!