Actually the 1TB 2.5" drives are available in 9.5mm height. 1.5TB 2.5" are available in 12.5 mm high and 2TB 15mm high.
The HD bay of the MBP will accept up to 12.5 mm while i think an optibay caddy will take only 9.5mm.
I don't know any Seagate 1 TB HDD which has 15mm and is meant for Notebooks, the STBD1000100h has 5400 rpm and 9.5mm.
There is a Seagate Constellation HDD with 15mm, but this drive is not for notebooks. Weight, shock resistance, power consumption are way too much for a notebook.
http://www.seagate.com/internal-hard-drives/enterprise-hard-drives/hdd/constellation/
And the 9.5mm 1-TB one that I looked at also had a high failure rate too. (That's what you get for trying to cram all of that storage in such a small place...)
Most Seagate 1-TB drives are 15mm high.
On my white, 12" MacBook, I am certain that 9.5mm is the maximum height.
But this post is about the newer Mac Laptops...
Debbie