Really depends on which OS .40 you have laying around. If you got something with a little more power then you might consider a OMP proyak ARF or a Mojo kit. I think the profiles are the best bang for the buck in the 3D category. I have never been a fan of profiles till I got one for myself. They are tons of fun and cheap to replace when you get too couragous and make campfire kindling out of them.