Toss the hundred level system. It's part of the way the video game rules represented the setting, and in the context of the video game they work fairly well. A tabletop RPG is going to have different goals, and you'll want to reflect the setting in a different way. There's no particular reason to keep the level system, the same stats, or much of a lot of other things in the setting. The moves are an actual setting element that you're working with and will want to keep, you'll want to keep things like the catching system and the technology, etc. Previous mechanical implementations? Those can all go away.

You might want to maintain some sort of level system, since the gain in power is fairly central. Maybe use 10 of them, which is enough to reflect differences between pokemon. For instance, the various bug-types might evolve at levels 2 and 4, while the typical starters might use 3 and 6. You might set a lower limit to certain types of pokemon. You might set moves to certain levels. Basically, 10 levels will be plenty.

In the actual games, pretty much everything major you get by level 50 or so, with the later 50 levels more or less being straight up stat upgrades. If you absolutely have to transfer them over via pulling from the mechanics, dividing everything by 5 and rounding basically covers it. With that said, you could easily make things a lot more open, going with a significantly less rigid interpretation of the setting.