UK Mortgage for Brit living abroad

Hi,

I'm a Brit living abroad and looking to buy a property in the UK.

We have a few questions:

1) My partner is a first time buyer and I am not - we are buying jointly so how do we get around the stamp duty?

2) What sort of rates are applicable for National's living abroad - i.e.: are we restricted to specific rates/products? (We're looking at interest free products only).

Thanks