Advice on how chances of a mortgage

Bugalugs

After a (financially) mispent youth I think my credit files are looking the best they've ever been, although I may not be the best judge of that. At 37, and in a long-term relationship we'd like to think about getting a mortgage.
At present I've got 3 defaults on my file. Two are satisfied (both credit cards - Capital One and Vanquis - both paid off and closed in Jan 2012). The other default, which I forgot about in the passages of time is one for £187 which states that it's a bank account which was defaulted in November 2008.
Two questions;
1. Would paying the £187 (which I think was a Lloyds bank account) be worthwhile, or should I just wait until November 2014 for it to drop off?
2. If we had a deposit for a mortgage at the moment how likely would we be to be find a lender? My wages are the main ones in the relationship, so we would need them included for the mortgage. How much deposit would we need?

Thanks for any help or advice. As with most people on this board, if I could have my time again I wouldn't have been so silly with my money. Nothing to show for all that spending on things that seemed ESSENTIAL at the time!