As it seems to be the season for it, I have been interested in putting together a small Great War collection of 10mm figures, aiming at a company for each of the major combatants in the West, some regimental or divisional support weapons, and a few "fun" bits like tanks and trucks and what not that give a good period flavor.
I have had a surprising amount of trouble finding online breakdowns of the composition of battalions during this period, with most of it being for 1914, and therefore not accounting for all the technological and structural developments that occurred as the war went on. When I was doing similar research for WWII I found tons of information. I guess since most of the battles were such large scale, that people must be ignoring the company/platoon level combat? To me anyway, the tactical aspects of running a company or battalion seems far more interesting than the more meat grinder aspects of clashing divisions together.
I priced out a couple of companies (at roughly 1:1) from Pendraken directly, and the Warstore as an importer. Interestingly, the Warstore comes out significantly cheaper, partly due to shipping (£19 from the UK, or $7 from NY), but each pack is cheaper as well.
The general idea is to "upsize" skirmish rules and have a 28mm figure replaced by a half squad/section base of 10mm figures. Obviously this will need some modifications, particularly with regard to "wounds" or movement ranges, but I think it will generally work well, and with some trench terrain, will look quite nice as well.
Over on TMP I saw a thread about WWI using Rapid Fire, and found this interesting basing system, where infantry figures are mounted in strips 15mm deep, and special weapons are mounted on 25mm rounds, which seems like it would work out pretty nicely.