Is there any way you could get a guarantor mortgage on it? I have a friend who has just signed an agreement with the bank to mean that if he is unable to pay for his mortgage, his brother (who is on a huge salary) would have to pay it for him. Obviously I don't know if you have anybody who you could call upon in that respect, but I just thought I'd mention it in case it was helpful.
I think that's a good idea in theory, but you have to be careful that you can DEFINITELY afford the repayments. Otherwise, your guarantor would indeed have to pay, and they may well not be all that pleased about it. You might think that your business is earning enough now, but just consider how quickly you could get replacement income if things go wrong. If you have savings, and could cover maybe six months of payments if needed, then this is a lot safer, and could work.