Customer user name tracking/database

I use a website where I sell items to people who have user names only (not email addresses). I need a spreadsheet or data base where I can track these customers and the types of purchases they make and how much they pay for items as well as when their last purchase was. I need to be able to sort and pull a list of user names separated by commas with certain criteria. I'd like to be able to pull a negative criteria as well (for example, they have purchased an email but have NOT done a phone call) There will be approximately 20 categories along with the date of last contact. I'm not sure what the easiest way to accomplish this would be. I imagine that an excel spreadsheet would be the easiest, but I'm open to other solutions as well. I do have hosting with Webair so am equipped to have something installed on my site if needed.