[Seven]

So if they look like the Charizard does, then they're part of the unlimited set. There's two variants of unlimited, there is unlimited shadowless and regular unlimited. You have the Latter, you can tell due to the picture and also the spacing of the four fire energy symbols. The shadowless variant has the four symbols a little bit closer to one another.

1st edition is usually denoted by a small number one on the bottom left hand side, right under the picture of the Pokemon.

The foils are obviously worth something, even if their plain old unlimited foils. I cannot speak for how they would be graded, as I never graded any of mine but it's typically worth to grade if you are selling, just like any other trading card. PSA slabs are king, and typically bring the highest.

Edit: I cannot speak to the "sell as a set, vs sell individual" I'd maybe consult an expert on that end.