
Hi, good question, lots of tests for collies and a good way of checking if you need them all is via the website anadune which offers, for KC/ISDS dogs a brilliant range of information on genetics and family trees.
You're right hip scoring is essential really, elbow scoring is optional unless there's a 'history' of problems in your line. These depend on the size of dog and the vet involved but also add in the cost of the panel to score it.
BAER is for hearing and some breeders do this, perhaps another 'optional' at the moment.
Critically important is a CEA DNA test which can be done in America or Australia - to test the status of your dog - clear, carrier or affected. Optigen in America do this. Depending on your dog's breeding you may also wish to consider TNS testing (in Australia) and CL testing (America). Whilst first cases of TNS were in Australia there have been english only breeding dogs found to be carriers - indeed it's believed that this disease was around a few years ago without a diagnosis.
You should also have the dogs eye tested for general eye conditions including PRA and also to pick up colombomas (not always associated with CEA)
The latest test to hit collies is for glaucoma - via a gonioscopy test done by the eye specialist along with the general eye test. This is a one-off test to check drainage angles and propensity for glaucoma. Again it may be worth checking with anadune to check susceptability but again it may not just be in australian lines (came to light about a year ago from an Australian dog imported into UK)
Hips, elbows, eye test, gonioscopy should be done after your dog is one year of age. DNA tests for CEA, TNS and CL can be done at any age.
For CEA, TNS and CL it's important that carriers and affected dogs (well CEA, TNS affected are unlikely to last that long and it's important not to use CL affected dogs for breeding) should only be bred to clear dogs - there should be enough of these in border collies other breeds may not be so fortunate.
Temperament is also important, it's critical to know the dogs in your dogs pedigree to check for compatibility with potential breeding partners.
Optigen have lists of clinics available and these usually offer postal participation (you'll need blood collection by your vet for this). Not sure how you do the TNS apart from it's Dr Wilton in Australia! Both places offer CL and CEA too - one blood sample will be enough for all tests.
Epilepsy is the main condition for which there's currently no test, unfortunately.
You should check hip scores of close relatives and their progeny - not just your own dogs the genes are complex and so far aren't actually identified, so dogs may have a propensity for HD even if their own scores are good it just means that if the 'wrong' genes come together you get HD
Hope this helps - there's a lot to consider.