Attachment Status and Extension Permissions

[Replicators]

On my forum i want to permit admins and such to upload very large files via attachments.I set the forums to stash the files onto the webserver instead of in the database.

Is there a way to have like a extension upload permitted to only specified usergroups?

Also i would like to see a counter thing being displayed on how fast your uploading,and a percentage of when it's done in the attachment upload window.

Also i tested uploading like a 10 mb thing and when it was done it gave me a error stating that the specified post couldn't be found or something like that.

If someone could make like a better attachment interface,and also where you could upload faster than you can normally,and also much larger files without a error occuring when it's done i would be the happiest person in the world.

If there is something like this already done,then i apologize.