I've been asked a few times to post this and I have on bns but since bns is basically dead I'm going to post it here for your enjoyment and criticism. I strongly dislike oversized gun models that look like they would be 6 feet long in real life and just look silly in game so I made it my mission to create well proportioned guns. With that said you don't have a lot of room to make a well detailed gun with it being that short so you have to choose your poison so to speak. I've been using this for over a year (p90 is new/I got tired of my other smg) and I've come to love it. The scopes I've been using for God knows how long and they give you an extreme advantage over players that use vanilla sights. If you don't like the gun models paint job or look then open slab6 and fix it yourself. If you don't like the scopes then open gimp or photoshop and fix it yourself. I strongly recommend customizing the game to suite your needs. This is merely what I use.
Edit: the skins are from the bf3 pack and can be found here Battlefield 3 [Ace of Spades] [Mods]
I recommend either using GIMP or Paint Dot Net for it