Integrating stackup with zerodev kernel

I am currently using simpleAccount.sol for creating SCWs. Stackup also allows using zerodev's kernel which according to the docs create better and future proof SCWs. So i need to clarify a few things.

(i) Do we need to signup for zerodev separately to use zerodev's kernel with stackup?

(ii) Do we need to pay separately for sponsored transactions if we integrate zerodev's kernel through stackup? I want to confirm this because zerodev also allows sponsoring txs but they charge 5% of sponsored txs plus 0.01$ for every transaction so which fees would be pay , zerodev's paymaster ? or stackup's paymaster ? or both?