The first thing to say, and it's easy to understand, that this is "elitist" and it can only be this way. You need active posters, you need respectable posters, you need people with a high knowledge of the EPL and you need people who are able to respect the others. You don't want a hacker in your league, right? Someone who destroys the work of the ones who work in it and act like a prick.
It's arfy's decision, but I would suggest a 12 participant league. This is 22 games, then you will have your FA Cup too, which will have 3 or 4 rounds, and if he pretends to use a double leg system, he'll need 5 or 7 games, which makes 27 or 29 leagues. Well, enough for the first year.
But the idea is that we have our Champions League and our UEFA Cup, in fact, they're starting next year between the Italians and the Spanish. Next year, you will have 5 or 6 games more and I guess a Supercup too. So it makes things more tight and remember you only have 38 EPL games and it'd be good to make room for any possible problem.
About the rules. I would suggest arfy to use a system that is as similar as possible to the Champions League system he already knows (BTW, he'll play it, since he was 3rd in the Spanish league last year). The Italians and us will have to adapt our systems to play in a common ground. If you already use th XT Champions League system, you won't have to make any adaption, which would be much better for you.
My view on it is that this goes beyond the usual Fantasy Leagues we know, as the one of uefa.com. You're not sharing players, you have your own players and you manage your own squad. You play "football games" against a particular rival, not against everyone. You'll have 2-1 or 0-2 results, not 67 points. I would suggest that you take a look to the Italian and the Spanish fantasy leagues forums and you can make yourself a picture of what I'm talking about.
I always forget about the usual fantasy leagues, for similar reasons as the one Mutu said. On the other hand, I found this game addictive. You have your team, your players, you have to be smart in your picks and you see the progress of your team in the standings.
I'm sure arfy will make a great job, because he already helped me to make the Spanish Fantasy League work. He has experience in it and I'm sure he can make it perfect since the first day.
I am wishing to help in everything I can. I have enough with the Spanish one and the European trophies that I will run along with Romanista10.
It's addictive, at least for me. I finished 7th
, but I made a great Copa tournament and I only lost in the final against that dictator called Iribar that won the Double. You won't regret to have this game.