Do saline implants come in high profile and can they be overfilled to 1400cc safely without rupturing?

Yes you could fill an 800 cc implant to 1400 cc but it will not look good.  The implant will be very round, heavy and will have a tendency to ripple and flip upside down.  Best to stay with the recommended fill volume of 800 cc.  

Dear Patient,I bet none of the doctors here have ever done such a thing as filling implants to 1400 cc...so far I have never heard of such a crazy number.sorry,F. Mussat

I have specialized in XL breast implants for many years. Every time that you overfill a saline implant you run the risk of it rupturing. There afre several ways to get the fake look-either with overfilled saline implants, custom XL silicone implants or XL tissue custom expanders.It depends really on what cc size to want to get.
You can think of a saline implant as a balloon. The manufacturer recommends an overfill of about 20cc but they have been shown to be able to be filled much more than that. They do start loosing their shape and can significantly distort the appearance of your breasts. 
 I do overfill espcially since the FDA has restricted saline and silicone implants to a maximum saline shell size of 800cc and maximum silicone size of 800cc. I do not know why that number was picked arbitrarily. 
So, I do do breast reconstructions greater than that with XL tissue expanders which do pride a greater diameter and projection and upper pole fullness and allow the size to be adjusted either up or down. Also, the shell of the saline implants are very thin and can dreflate more easily. You may want to visit my site below which explains everything, esp for XL sizes which is my specialty, either initially or revisional surgery.