I hope my post can help you build one. I am basically outlining why the BFI from AirFlowInnovations is the best choice, and if that is completely out of your budget, I hope you can take information from this post and apply it to your build.
Bernoulli's principle is used to explain fluid dynamics and how fluid can be accelerated by the change in pressure. It applies to gases that are unchanged as well. Air entering the BFI at the Large 6" opening on the high-flow filter will flow into the TB and move from that 6" opening to a 3.5" elbow that mates up with the Throttle body. A property that effects Bernoulli's principle is that of friction and resistance. The air entering the intake is moving so fast it is unable to change in temperatures enough to affect the principle itself. The design of the BFI allows it to reach air from a pocket away from the engine heat and in route to the Throttle body, the flow is extremely smooth without any friction or resistance
If you can make a HomeBrew intake taking the principle of (even if you arent able to utilize a gradually decreasing Diameter) smooth flow and velocity you will have a winner. Try to start large at the filter and allow it to smoothly flow from the filter to the Throttle body without any sharp decreases in tubing sizes that would cause turbulence (which negates the velocity principle and smooth flowing air). I think any intake with an open element filter will be louder and might enable a slightly better flow of air, but to increase performance and to add a killer sound, the large metal resonating smooth tube of the BFI is the best example.
Hope this helps a little. I have no personal examples of a homemade intake on a 4.7 truck for you, other than what I have seen online.