How would you structure this Sub-to deal

[Dani Beit-Or]

How would you structure this deal:

SFH in Belton MO (outside of KC)

Asking: $270k

Our offer is: $255k

Seller has a current mortgage balance of $143k, int. rate ~3.1% and a monthly P&I of $665.
If we do a straight forward sub-2 then we need ~$112k. But I want to bring less and looking to do 10% (~25k down).

So there is a gap of (255k-143k-25k=) $87k.

What are my options?

My thoughts are for the seller to do a 2nd for the $87k BUT the concern here that a 2nd may increase the chance of triggering the 1st lender.

Looking for idea

Thanks