mmmh; I've got the X70 (I think - the labels are removed) from montague and have used it for some trips, even about some hundrets of km.
there's no real difficulty to put carrying-platforms at it. at front, you can either use "swing" by tubus http://www.tubus.com/product.php?xn=65 (which I have) or if you prefer a real lowrider this one: http://www.faiv.de/
at rear you can use either model, but if you want to keep your bike foldable, you caould use the quick-rack from pletscher: http://www.pletscher.ch/wDeutsch/pages/Produkte/index.php?IdTreeGroup=13&IdProduct=12&navid=10
the folding-mechanism makes this bike somehow heavy (I think about 3kg more than a bike without it)
really bad is the possibility to lock the bike due to the one-maintube, so it's cumbersome to lock the frame together with the front-wheel to a fence or similar.
with the knowledge of this I'd take today a model with a double-maintube such as this: http://www.montaguebikes.com/pavement-folding-bikes/
these doesn't seem to have suspension forks, which makes it possible to mount any front-carrier and the bike won't be as heavy
note: any additional part at the bike makes it more diffcult to fold it down.
a bag for a bike with 2 rear, 2 front and one handlebar-bag is for example the vaude big-bike-bag: http://www.vaude.com/epages/Vaude-de.sf/de_DE/?ObjectPath=/Shops/Vaude/Products/15257/SubProducts/152570400
warning: my bike with full luggage for a tour is about 50-55kg, so this large bag is a bit bulky, but it's possible to take it within german ICEs (long-distance-trains), where bikes are forbidden. well the train must not be overcrowded and there are not many places for this bag...