For anyone that might need the information,
1.- Do not trust in vendors, please check very deep with the manufacturer of your equipment all specifications, if RAM can be upgraded and specially if motherboard supports SATA 6Gb/s, almost none supports SATA 6Gb/s, I had to return the PC of a well recognized brand to a store that I am not going to mention the name.
2.- Finally I found BestBuy, Flamingo in Sunrise Fl, In that store I was able to find the computer that can run a Series 520. They requested the SSD and the 8GB RAM expansion for me and will deliver next friday. If it works fine I will mark my question "answered" but by myself.