I've found the Mikrotik SFP+ switches to be pretty permissive about SFP+ modules. I've used Mikrotik, Juniper, Cisco, and "generic" ones without much trouble. I think you'll find good results no matter which you select.
If you are looking for new ones and want to order from USA rather than China you should check out Fiberstore - fs.com. Their modules are generic but are available with various manufacturer id's (keyed for Cisco, etc.). SR modules are mostly $18. I don't know that you'll find new ones any cheaper unless you order off ali-express.