Smid, you can do it though I'd also love to as well. I think it would be awesome if we could mesh together Antilia and Coalition Diplomacy; get fifteen people to sign up, randomly select them for party size, then allow them to submit a brief party description fitting in with Antilia's history. You/Me/Colin could have veto power over people's party submissions to make sure there aren't any silly ideas or parties too similar to each other. Or we could come up with the parties and assign them to people. The negotiations to form a government would happen as prescribed in Coalition, and then once one is formed everyone could roleplay a legislative session for a set period (I'd write up the rules beforehand) until there's a new election, which may require rules/roleplaying as well and also be based on how I/whoever, as GM, decides how the coalition and legislation affects each party's vote totals. Then there'd be another round of negotiations for a coalition to be formed, and everything would go 'round again.
This all sounds good. I'm happy to assist in whatever way you consider appropriate. Taking the Coalition Diplomacy rules as they are written is fine - with the fifteen parties, but I think from an Antillian perspective, having fewer parties with specific descriptions is best. If you and/or Hashemite and/or Colin define the relevant parties, people could then decide to join those parties at the start. That's assuming that the emphasis will be on the parliamentary procedure and debate/government sim side of things. If the emphasis is to be the coalition-forming side of things, certainly stick to the rules, because they're well written and easy to understand. Perhaps divide the major parties into factions (for example, the major left-wing party could have populist and progressive factions within it - this would leave more room for negotiations within caucuses, between the factions). In this way, people could join a faction as well as a party, and their positioning within that would lead to the sort of jockeying for position that you see in the Coalition Diplomacy game. The GM could manually set the number of MPs in the faction/sub-faction belonging to each player - this would be a symbol of how influential a player is and players could in this way be rewarded for activity levels and the quality of their debate. These numbers would again be adjusted following elections.
As for the legislative session - I'm happy to help with procedure, I know some of the real life rules regarding that. You could also potentially look at Bills and Acts from real life and introduce those into the Parliament as Bills for Antillia - this would prevent people having to put forward a specific legislative platform and write legislation and would allow people to focus primarily on debate and elections.