Out of Ely, Talk to John or Lynn at Voyageur North Outfitters for a canoe rental. Good folks. I use all my own stuff, but know then from a forum we're all on and stop by top say hello when I'm out that way or i see them at trade shows. I also know a lot of people who have used them for many years. If you want a shuttle, Anderson outfitters on Crane Lake can take you on the international line up the Vermillion River and bring you to the mechanical portage at Loon and into LaCroix for a drop and pick up. Go up into Snow Bay and take little lakes like North and Pocket River to explore little water back out to LaCroix or just stay on LaCroix.
Up through Agnes and into LaCriox is a nice trip if you do not like portaging. I like the western side better, especially the summer months because of the burn areas still bouncing back.
The Little Souix (#14 I believe) up into Little Loon, north up through Slim and those lakes up in the "inner horseshoe" area of western LaCroix are not used much. Doesn't take much to not see many people at all, after you leave Loon and Little Loon.
Got two trips planned for this year. One in BWCA and one up through and into Quetico.
I can't really suggest a 4-5 day loop because my trips are never under 8 days, but I know there's tons of great options.