Bolt Action Rifle Civil War - Game recommendation to create a Campaign Mod in?

[spelk]

Apologies for convoluted Subject title...

I have a guy asking a question over on the computerwargames subreddit that I run, which is basically just a place for me to post up computerwargame links I find...

http://www.reddit.com/r/computerwargames/comments/2shaip/suggested_game_to_build_a_campaign_for/

anyway, he's asking if there is a wargame he can build a campaign mod for that satisfies his area of interest in... 

I've been working on a realistic simulation of a civil war in the Model England of the Model house of commons on reddit, and I love war games. I was wondering what games you would suggest to build a campaign onto.

For reference, the war takes place in the 21st century, makes use of mostly bolt action rifles for the early stages, and the forces are organized in a moderately conventional manner

I'm a bit stumped, so I wondered if anyone here could help with suggestions?

[jomni]

Age of Rifles.

Did he say FPS, TBS, RTS?

[Bison]

Perhaps Advanced Tactic Gold, but I'm not sure if you could build a link campaign.

[bbmike]

Maybe one of the Strategic Command WWI/II games? They seem to be highly moddable.

[Jarhead0331]

What about pike & shot? That platform seems to be fairly moddable and it already deals with the English Civil War.

[spelk]

Thanks for those suggestions everyone. Much appreciated.