Offset mortgage - use a broker?

Imelda

Hello
we are in the process of selling our house and buying another.
We currently have an offset mortgage with First Direct which is fully offset.
We will need a new mortgage for our purchase and were thinking about another offset. We will be borrowing around 20%-25% of the value of the new house.
The reasons we would prefer an offset are:
my husband usually gets dividends and bonuses from his job which means his pay is quite erratic, many mortgages have a 10% limit on overpayments but in good (🙄) years we can overpay a hefty chunk but with the knowledge we can borrow it again if necessary.
The houses we are looking to buy are doer - uppers and so it will be useful to have credit easily available and we can offset our renovation budget whilst we obtain plans etc.

I know not many lenders offer them and so is their any point using a broker? We are both employed and we are looking at borrowing 2x our combined basic salaries, it *should* be straightforward (famous last words!).