Hmmm that is difficult, as I'm confused by your question.
You want a mod chip for a PS1 to play Atari Legends (probably Tempest with a mouse hack) and a vertical screen, but why would you want a mod chip in the first place?
I was in my local goodwill store and they had a ps1 there for $15 and the games you indicated are $1 or 2 on ebay or your local games store.
So your question is moot.
The answer is: BUY THE GAME

See no reason for the mod chip eh?