If you have dedicated server for your website, then you can use upto 100000 Customers to import/export
Contact us at firstname.lastname@example.org
What customers say about Customer Import/Export Suite
Extension working with Journal, OC version 184.108.40.206, but password uploading doesn't work (in plain text). Tested many times, different account and different password, but with same result.
Great extension, allows me to import customer custom fields that show up in the customer's account profile. Very responsive to my questions and solved any issues I had.