Got it, thanks for clarifying!
If you just want to use the SNS canisters as a basis but implement you own additions, you should be able to set the minting account to anything when you deploy the ledger canister. If you chose any canister other than the governance canister it might however be trickier to implement voting rewards (if you want them to consist of freshly minted tokens).
If you want to use the SNS “out of the box”, then by the Carbon milestone it will have a first simple version of a reward scheme, where the SNS governance canister will indeed be set as the minting account (minting canister). The design is however still in the discussion phase (see here). This is just a first version however, so it might be possible to make this configurable later (e.g., for SNSs that don’t want voting rewards, with voting rewards that are minted this would be harder).
We will also have a community conversation about SNS rewards next week if you are interested! It will be held by @bjoernek who leads the work on the SNS reward scheme.
(Bjoern, please also feel free to add details that I might have missed here).
Hope that helps, please let me know if you have further questions!