When you've had this many babies you are more than likely already a little dilated now due to the pressure of the baby on your cervix. The fact that it is already starting to shorten is a good sign. I would try to negotiate with them to not use the syncto drip unless absolutely necessary, and then only on the minimum dosage. It would be best to try to avoid the Gel, as once it is in, it cannot be stopped and if you are hyper sensitive to the drip, then the prostin pains (after effects of the gel)could be quite painful for you, whereas the drip can be turned down or off altogether. But if they are able to break your waters then you may not need any of that and labour will start on it's own once they are broken.

As for dealing with the pain of the contractions, you already have yourself a Doula so that should be a great help in that department - she will be able to keep you focused on what you are doing and she will have tools to help you cope mentally with it. Try to keep as active as you can and make use of the shower or bath if you need to. Another thing would be to ask if anyone at your hospital is qualified in giving sterile water injections as pain relief - water is injected just under the skin - and some women swear by it as a natural pain relief method. Good luck and I HTH.