Just got some figures - bare metal as of yet, but enough to think about basing. In the fiddly trade-off I was thinking about avoiding too-fiddly manipulation by using 30mm square bases. Problem is, two ranks of figures looks good for concentrated troops but is a bit chunky to look like an extended line.
So, the plan. I think I will go to 30mmx15mm infantry bases. This gives a nice extended line look (1 rank, 3 figures). To keep the manipulation down, we will use a stand = 1500. This will give a nice look; concentrated troops can be represented by putting one stand behind another. The counts would be 6 stands for a French division and 8 for a Prussian
Guns will fit nicely on 20mmx30mm - this will reduce the frontage down to 200m; I might want to differentiate French and German divisional artillery by frontage to allow for the extra battery.
Cavalry I am uncertain about - 2 figures looks OK on 30m square, and will just fit the depth on 30x20. Two upon 20x30 is also an option. In any event, Cavalry are bit players so I am not going to worry too much.
Pictures to follow as we get some lads painted.