I am looking for a desktop replacement laptop.

1. Preferred Brand: no preference
2. Budget: no budget
3. Usage: Microsoft Office application, surfing Internet, stream/download YouTube/movies, VirtualBox/VMware application (2-3 any at given time)
4. Preferred laptop/screen size: 15"-17" (preferred 17")
5. After Sales Support: On-site preferred
6. Storage: HDD or SSD, at least 256GB
7. I/O: USB2/3, HDMI and/or VGA
8. Connectivity: 802.11n/ac (at least dual band 802.11n)
9. Memory: 8GB expandable to 16 or more
10. Others: Pointer (nipple in the middle of keyboard that performed like mouse), touch screen is optional

Thank you!

I went to ILLEGEAR website and found their S-series, R-series, D-series and Q-series all have 17" models. What are the differences and how do I choose?