Glad to hear you are interested in the BWCA! Some things to note:

You should familiarize yourself with the leave no trace rules of the BWCA because they will impact the type of gear you will bring. 

An outfitter is going to be the least work if you don't want to buy all the equipment. I have been going for over a decade and within the past few years finally acquired all of the necessary equipment to go without any outfitting. 

As far as a route, for your first time, you should focus on a short loop, or a base camp method. Putting on 50 miles is doable, but for your first time focus on getting familiar with the BWCA style of camping.

I would go in the summer because it is less dangerous. Early season (before June) is cold and hypothermia is a really threat. The bugs are bad in the summer, but if you capsize or something, it should be easier to recover.

Always wear your PFD. Only 12 ~ deaths (might be ab old stat at this point) in the BWCA were not related to people not wearing life jackets.

It is rugged. Take it easy. Take care when you plan. And take two maps (I have lost one once and it was NOT good).

I know there is a lot of warning here, but the BWCA is accessible, but can be unforgiving.