Anyone who enjoys fantasy football (soccer) please read!?

I am thinking about creating a fantasy football website that includes not just the Premier league fixtures but also the Italian Serie A and the Spanish La Liga. I also want to include a live january transfer window where players on the site can only trade their players for others during this period between other members. The remaining months will allow members to transfer players as standard. All of what I have suggested so far will be a free to play version. I welcome any feedback or further suggestions. If successfully implemented, I would aim to expand the number of players members can pick by having more leagues. But for now, I just want to stick to the 3 main European leagues as one fantasy game (this was because all three leagues have 20 teams, with the same number of fixtures).