Hello! I am looking to buy an iMac for my real estate office. I decided on a desktop because it will motivate me to keep and do all of my work within the office. Unfortunately, I know very little about technology. I am comfortable with apple because I have an iPhone and an iPad. My hope is to utilize the three together. I need a desktop that will be enough power/storage to upload pictures and videos of homes and do/store basic paperwork such as spec sheets, contracts etc. I will spend whatever necessary but do not want to be wasteful on overkill. I have considered buying a used iMac on ebay but I'm not opposed to buying new. I am also curious if anyone has a preference on the 21.5" or 27" screen size. There are so many options I am overwhelmed!! Thanks in advance for any help you may have to offer!