I'm not completely understanding your question. What is the purpose of each of these 5 mini-sites? Is there purpose ONLY to link out to other sites that you own. Or are they stand-alone sites that have a purpose of their own?
If you want good quality inbound links that the search engines recognize and count towards your Link Popularity and Link Reputation, it is best to get those from other established sites that you dont own.
If you were to set up 5 sites at the same time, the interlinking would be practically worthless in regards to Link Reputation - because all 5 sites would be too knew to do you much good in that way, and because you own them all and the saerch engines would look at it as 'manipulation'.