Help with home system centered around Mac Mini server and 2 iPads.

Hey guys - sure this question has been asked ad naseum but I could not find too much relavent. My 2008-2011 Apple suite is slowly kicking the bucket and it is time to invest in all new.

Current setup:

1- 4th Gen MacBook - limping along.

1 - 5th Gen Unibody MacBook - good to go.

2 - iPhone 3GS - Soon to be replaced by iPhone 5 in July, both limping along.

1 - 3rd Gen AppleTV

1 - 2009 circa AirPort 802.11G, limping along.

1 - 2nd Gen iPad 32GB WiFi+AT&T 3G

Proposed setup:

2 - iPad 4th Gen

2 - iPhone 5

1 - 3rd Gen AppleTV (stayover from previous setup)

1 - AirPort 802.11N - replacing 802.11G due to WiFi speed limitations in high density community.

1 - MacMini Server

1- External drive to backup the MacMini

So the plan is to ditch the laptops and replace them with iPad accessing items stored on the Mini. Combine iTunes music through importing and create one account for future purchases. Purchasing an external drive for backup of the MacMini, horror stories on the TimeCapsule has me steering clear of that.

In my mind I may be envisioning this to be an easy feat. Should this be as easy as I am imagining it to be or do I need to be worried about anything else that I am not thinking about?

Thanks in advance!