Where can I find breeders for the above, or rescue/rehome?

I suggest your local rtescue hom may have crosses of various sorts.  there are some people charging silly money for a cross breed with a cute name, I certainoly wouldn't expect to pay anywehere near the price of a good pedigree pup though you are likely to be asked much more for this cross by those deliberately breeding them.  If the parents have Hip and Eye Cewrtificates from the BVA then slightly higher than average mongrel/cross price would be acceptable to cover the cost of these for the parents.

I would type in the word Labradoodle in the search facility on this forum and you will see that views are quite heated about this deliberate cross breeding with the majority against.  Main reasons being is that they are not a breed if you are still using first crosses, and as with any cross the results are totally unpredicatable.  If you breed on from the pups then things are even more variable as to size type etc of the pups.