It's not a bag, but for
FoW I've really been taken by the Plano six tray hip roof tacklebox:
http://www.planomolding.com/fishing/plano-tackle-systems/tray-boxes/861600.html.
The bait racks fit medium and small size bases just fine, and with a bit of foam to separate them you can probably fit 2 teams in each one. The larger compartments pretty easily handle the bigger bases for artillery (though some height checking may be required) and medium tanks fit into the spinner racks as well (at least Panthers, StuGs and Pz4s do). The box is very sturdy including the handle, stackable with other boxes, and has good heavy brass latches. I've driven with them back and forth a few times and the models don't seem to shift very much, if at all. I will definitely not be good if it gets dumped over or dropped, but the box itself seems unlikely to do that if you situate it properly to begin with. You can also put locks on it, though that's only going to keep honest people honest and not really deter a thief in any way.
In the bottom I usually put another smaller Plano box with dividers for more infantry teams similar to
http://www.planomolding.com/3600-stowawayr-utility-box-513.html which will accommodate another dozen or so teams (usually platoons that are less likely to hit the table). On top of that I have some foam and then the larger vehicles that don't fit neatly into the upper racks.
Overall carrying capacity would be almost any 2000 point force outside of maybe Strelkovy. In a "I really wouldn't recommend this but it's doable" setup in the "vehicle" bay of one I have six Hummels, 6 King Tigers, 8 Tiger Is and 3 Jagdtigers. It's a decent amount of volume, and you could likely fit a couple of normal pluck foam trays in there if you wanted to go that route.
It's certainly not as flashy as the bags from other manufacturers, but it's fairly commonly available item in the US (not sure about in the
EU for the
OP though). Total cost for transport comes out to roughly $41 USD at normally found prices for both boxes in the US. I lucked out the other day and saw Amazon had the big box on sale for $15 so I snagged one for more Armada carrying space. Toss in some foam from the vendor of your choice and you have a decent solution for (probably) under $60.