Offset Vs deposit

Looking to buy an apartment. Want to keep payments to 30% of take home pay. Arbitrary figure but I don't want the stress associated with a huge debt and it reflects my risk appetite. Should I:

• put extra cash towards the deposit, take a smaller mortgage and forget about it. Or,
• keep the deposit at 20% but take the maximum mortgage possible and put the extra cash into the offset.

I think these will result in the same monthly payment but wanted to sense check.