I am not familiar with these vendors.
If you look in the vendor connection forum and search here (or better yet google with "site: GLP1forum.com" at the end of your search term) you will find at least a dozen vendors that have been used extensively by members of this forum. You'll find both good and bad experiences, read through and based on what is important to you (cost, quality, 3p testing, speed of delivery, payment methods supported etc) you can make a more informed decision. Vendor COA's are decent first screen tool but useless beyond that. You have no idea if you will receive what they tested regardless of what they tell you.