Well, like I say, I don't want a Labour-SNP coalition, and I'd be worried that such would be a disaster for the UK. But if it is to happen then it had better be more Labour than SNP. The more power the SNP have, the worse things will be.
So I'll vote Labour, and hope that down south things work out to ensure that, one way or another, the SNP don't get any hold of power. As far as I can see, our best chance of this is to keep the SNP out. Which means a vote for Labour. Not ideal, but it's the best I can do.