Upload Space Limitation for Network Setting & Pro Sites

Hi

I know there are few different settings for Upload Space where we can control them in Network Setting or via ProSites.

I just want to know more precisely on what are the best ways I can implement these: –

(1) Limit the Total Storage Space for Different User Groups

(2) Limit the Total Upload Space

(3) Limit the Upload Space for Individual File Size

(p/s: are total storage and total upload space the same thing, or actually are 2 different things)

Can I just do the above setting via Pro Sites and the Default Network Setting, or I need to integrated them with WHMCS.

And I would like to get more clearer picture for these:

(a) Upload Quota (ProSites) – “Allow you to give additional upload space to ProSites” – this is talking for Total upload space or per file size

(b) If we set the upload / storage space limitation via Pro Sites and the WP Default setting, where we can see the total usage per user?

Thanks in advance for any assistance.

Much Appreciated.

Sylvia