My take on this is to buy an Aeronaute and a Tristar or 2 Tristars or one Aeronaute and a Western Flyer or a Tristar and a Western Flyer.
We know that you can pack really light with the Brain Bag and your wife could try it using Lani's wonderful tips, she could even supplement her wardrobe in Europe.
With multiple modes of transportations, I strongly advice against check in bags. I was born in Europe and travelled there by trains, buses, boats and Ryanair before their stringent weight restriction.
There is no checking on train, bus and boats, you have to carry the huge rollaboard while navigating train stations stairs, the mazes that are bus stations and on steep boat ramps.
One good thing about that is your will be both very hungry for European foods and will be able to proudly show your newly gained muscles. The not so good thing, it gets exhausting pretty quickly.
Especially when jetlagged.
Ryanair and many local airlines force check in oversized and/or overweight luggages. Overweight meaning as low as 6 kg.
Which means you have to check the airline website for their current weight limit, with the price of oil rising, it might change, so you have to buy a luggage scale.
I think they also charge the check in luggage by weight, so wheels mean more expensive.
Because European airlines are busier than ever, there is a strong likeliness of routing the bag in the wrong direction
The best wardrobe bet in Europe is one or 2 neutral color basic pieces that can be dressed up and down. One pair of comfort shoes for traveling and walking and one pair of lightweight dressier shoes like a ballerina flat or a lightweight equivalent for men. (Europe has wonderful shoe makers, you can buy the extra there as well)
Make sure the walking shoes are waterproofed. One poster talked about Londrain, Amsterain and I can add Parisrain, Bruxellrain and Berlinrain.
You have more chance of sunny weather in Spain and Italy but I remember one picture taken by a Tom Bihn fan of Rome under snow in winter, which means they can get rain in the Fall as well.
Check the weather forecast now and periodically until the day of departure.