I have only played a few games of FoB but I will try to answer your questions.
-“Do you think they could be modified to accommodate larger unit sizes (say 6-8 bases per battalion, purely for aesthetics?).”
Yes, in fact the author addresses this issue.
-Skirmishers
Some units can be deployed in Skirmish/loose order formation but only those that fought exclusively in that manner. IE dismounted cavalry, Guerrillas, “native” units etc…
-“would you mind expanding on the card idea?”
Each army has a “sequence deck” the composition of which is determined by the skill rating of its Commander and Chief. A good deck will have a higher number of movement and maneuver cards, while a poor deck will have more lull cards which allow no action to take place (or the enemy to steal initiative!) At the start of the turn, both commanders roll their leadership die and the winner determines who acts first. The difference in die rolls equals the number of cards that may be drawn randomly from the “sequence deck.” These cards are played one at a time and units may or may not act on the card. All movement, formation/facing changes, melee initiation, and rallying can only be performed with the appropriate card. As I said in my earlier post, units may fire at any time but cannot fire again until a firepower card is played. It sounds more complicated than it is; the system is in fact quite elegant and in my mind appropriately models the “friction” of the battlefield.
-“i don´t want little units, and i think i don´t have to refight a big battle to have fun.”
There is a recommended basing scheme, but no required base/unit sizes. I base my 20mm infantry 4 on 1.5 inch square with four bases to a battalion. This gives a unit frontage of 6 inches, with a regiment in line taking up 12-24 inches of table top. I play on a 4 foot by 8 foot table so I don’t refight “big” battles either!
-“FOB is a "quick play" version, but have you tried the other and is it that different?”
I have only played FoB. In “standard” Piquet the players do not get equal opportunities to act, and units must spend initiative points (the difference in leadership die rolls) to act on cards individually. This can result in one player marching up and down the table in one turn and the other may only act once! I like this idea…I understand Les Grognards has more “chrome” or period specific rules as well. I will probably look into it eventually, one rule set at a time!
I hope I have been helpful, as I said I have only played a few games. Check out this site for some good AAR’s using the rules:
http://web.mac.com/nataliendpeter/Site/PM_SYW001-1.html