Always the Porygon! I am biased towards promos so will always pick a promo over a regular set card, regardless of the grade. Not to mention something iconic as the fan club Porygon.
I’d go with the Porygon. It just feels more unique than a no rarity Raichu. No rarity is cool though, don’t get me wrong, but just look at that Porygon
It has better fundamentals and appeals to a larger group of people than a PSA 9 Raichu No Rarity Symbol. I think you’d also enjoy it more, aesthetically speaking.
I would personally go for the Porygon. I like that there’s a story behind the card besides just being the “first” and the game room in the background brings me back to my childhood!