It's sorry to say that only local mom and pop shops care enough to engage in discussion, and even then those are rare and could still get bogus advice. That's kinda why forums have been well liked for decades now: Bad advice get's noted and you can glean all the key points and go from there.
If you can be more specific with your needs, we may be able to assist more than some mega-million dollar store that wants to sell you anything. I'm lost on Win8 and touchscreen (because I don't care yet), but handling 200M files and processing video is right up many alleys here. SSD are king, but do you need high I/O, flat out speed, or would just storage capacity be a concern? Agility 4 256G drive would be my generic Go-to (it's $150), but if I/O's matter that much then you may want a high-end enterprise drive. Video differs if your software utilizes CUDA or if it leans on your CPU for rendering. If CPU, then is it able to handle 2, 4, 8, or 16 threads?