Hi Cortes, that Leben integrated is a sweet unit. I've heard them driving Harbeth compact 7s beautifully. I don't know how they'd sound with Unifield 1s though.
I have a pair of 300B Paralled monos that do a couple of watts more than the Lebens. I'll try them out with my Unifield 1s to see if there's enough juice and let you know in a few days. I'm not very optimistic though. I'm currently using 50wpc SS monos and they seem just right. I'm expecting that 15wpc might limit music to small ensemble affairs.
Oh, and yes the U1s can be put close to walls and still image well. They are front ported. If there's too much boundary reinforcement in the mid-bass region, all you have to do is stuff the ports with a bit of dacron.