We have done testing with the Emlid Reach but we were using RTK. When you use a Rover without a Basestation is when you would need to carry out PPK, hence the reason you're asking . I have done this in Trimble Pathfinder, but a lot of our customers will use Trimble Bussines center. You can download a free version of the base software on their website.
Picking a CORS station is requires some knowledge of the software you are using to carry out the post processing. This is a great article that is very worth reading regarding the topic. Here in California the ground moves fairly often so it's important to take things into consideration. When I worked as an analyst in Colorado I frequently used stations in Wyoming and Montana.
Looping back to the Emlid. They have amazing customer support and you can usually get them on the phone if you are seriously considering purchasing a unit. Please let me know if you have any other questions moving forward.