To connect to more than 5 UltraPeers you will need to become an Ultrapeer yourself. To do this you need a fast connection and be able to recieve incoming (meaning no brickwall). I don't think it works using UPnP. You will need to use portforwarding in your router/modem and allow exceptions in your software firewall and maybe your router/modem as well. Your Modem/Router will also have to have the ability to deal with many connections at the same time and you'll have to run This Patch to get more halfopen connections (if using Windows XP with Service Pack 2)

I think the max is 32 Peers and 32 Leafs when running as an UltraPeer

(most I had is 26 and 31)