Hello - i'm currently hitting a bit of a mental wall when it comes to building an on-ramp for customer funds into my app. I want customers to be able to use their own funds to effectively load funds into my app for their account, and am trying to figure out the best way to do this. Right now my setup is as follows:

Customers have 3 options to on-board funds:

1) bank account - ACH transfer and they are credited with that amount of tokens in their app wallet

2) PayPal / other CC on-ramp - buy our tokens with their credit cards while incurring a fee and we drop in tokens to their wallet

3) Crypto on-ramp using something like Binance, Coinbase, etc.

My focus is on the 3rd part. What would be the best way for on-ramping to occur? I have the stellar-based token already set up on the Stellar Mainnet, but would it make more sense to build something akin to a front-end ERC-20 token? Basically an ERC-20 token that can live on an exchange like Coinbase or Binance and then on the backend we do some sort of atomic swap where once we receive someone's ERC-20 token we can give them the proportionate amount of backend stellar tokens so they can use our network? This way we have some greater reach by being able to integrate into MetaMask?

The other thing about this set up is that is has to work with user off-ramping as well - customers need to have the ability to convert that token back into fiat so they can transfer it back to their bank account once they're done using our network.

Any help would be greatly appreciated!