Hello, my name is Thomas and I’m trying to create a game on Unity 5

About the game :

It's a Koi-Koi game (using Hanafuda cards), it’s played on multiplayer online and whole the part concerning the game mechanics is almost finished (the scoring is in progress). I make this game because there are currently no Koi-Koi game allowing online multiplayer.

Why I'm here:

I use currently copyrighted textures (to focus solely on the game mechanics and the online), its textures are extracted from a site what sell cards Hanafuda, ditto for the background that is a wallpaper find on the internet. So I come here to ask you for help or at least ask the difficulty of the task and have an estimate. I would have 48 cards and a back hanafuda cards and finally a background.

The style:

A modern look, simple, refined, vectorial if possible or with high resolution. To give a comparison: http://www.kelseycretcher.com/hanafuda.html something in that style (that is just an example to give the idea)

Open Source:

Probably, once the code is perfectly complete with commentary.

Thanking you in advance for your answers (and with apologies for my english, I'm french = / )