Every hard drive are Mac compatible. It's only the format you apply to it
What mac are you using? I working on mac at the job, I could help you out
If you have any thunderbolt connection, try to get a thunderbolt hardrive, they're quite expensive.. But otherwise, a simple usb 3 hard drive is enough.
LACIE are great, just a bit expensive. Any other external hardrive will do the job. Just make sure to format it once you're on your mac.
Application > Utilities > Disk Utility. Once you're on it, Click the hardrive you'd like to use with your mac -> Partition, put one, choose the name, and put "Mac OS Extended (journaled)" or exFAT if you want the hard drive to work on mac and windows. Partition and you're done.