I bought my 17” laptop from Tiger Direct (www.tigerdirect.com)
Alienware makes good higher end systems
Expect to spend a $1,000 or more
You can get a laptop that has a SSD drive and storage space for a 2.5” hard drive. That extra storage you use for everything including a backup of the SSD files. A 17” one could have two 2.5” drives and a SSD.
3 drives
Example here: https://rog.asus.com/articles/g-series-gaming-laptops/g771-upgrade-guide/
2 drives
https://rog.asus.com/articles/g-series-gaming-laptops/upgrade-guide-rog-gl552/