Hi Alex- if you haven''t already check out the "diamond vendors" listed under the resources tab on the top of the page..lists most of the popular vendors everyone works with on this site. I personally worked with Whiteflash.com and JamesAllen.com and had a very positive experience with both. I personally like the fact that JA offers a 30-day return policy and trade-in policy as well as free cleaning/polishing. Whiteflash also has amazing information online for their loose diamonds and will answer all questions you have. You may just want to do a search for the vendors you are looking into to see the feedback they have received. Good luck with your search and keep everyone posted!