For the price of a Small Claims action, just get it started - if it does nothing else, getting a CCJ on his record will warn others off. While the court process is happening you can do your investigating of his assets.

There are websites that show when a house was sold and for how much, and some of them can tell you who the buyer and seller were, but I don't know there is a way to check his debt on the house. If you get judgement, slapping a lien on the house (if he is the owner) will stop him selling until you are paid, but if its just in the wife's name it doesn't work.