You can upload unlimited WA channels into any version that you purchase without any restriction what so ever.
You can also register your own channels using Manual Channel Registration Tool module along with automated WA channel registration using several API support for different channel providers integrated into the panel.
But, just make sure that your server configuration is upgraded according to the amount of channels you upload into the system.
For Marketer & Reseller Edition with up-to 10,000 channels 20$~40$/month plan is enough on digitalocean.com
For Developer & Enterprise edition we recommend using 40$/~60$month plan on digitalocean.com for robust and smooth functioning of the script.