Most lenders are very cautious about temporary/contract workers and generally say no to them. You say you work regularly on 3 month contracts but you dont mention if this is continuous employment or whether you often have breaks in between contracts and this could be the crucial element. If you can evidence that you have workd without break for a long term (2-3 years) on the same job under the same terms and conditions then a couple of lenders may assist you. If you have had breaks of contract or time away from employment then I doubt any lender will help you.
You would be best to base all property searches based on your hubby's income alone. if you allow roughly 4x annual income for how much you can borrow (plus anything you may gain or lose on your existing property) then you will get a rough idea of what properties you should be looking for. Some lenders may allow as much as 5x income if your credit is strong