Air Intake Relocation Advice

[firejackal]

I want to clean up my engine bay a bit and relocate some stuff. After i fix my trunk leaking I'm going to relocate the battery to back there like i did on my other cars. After that I was planning on relocating the air intake pipe to where the battery was.

So my question to you guys who has done it, is will this cause any unforeseen issues, and will I have much room because of the maf and the temp sensor? I plan on making it modular like i did with my crx for i can switch between running the filter in the engine bay, to the fender depending on the weather conditions.

I was told by a few people i could cut up my old plastic intake pipe, but I'd prefer to buy some mendrel U bent steel pipe from jegs.

Just pictures for reference, my engine bay how it is right now. Ignore the valve cover, I'm in the process of sourcing another one for i can fix a few issues on it.
http://i.imgur.com/n6VwckB.jpg

And the maf, I'm guessing air temp sensor, and the filter as it is right now:
http://i.imgur.com/YN47adO.jpg

Also off hand, does anyone know what the proper pipe size is? Is it the same at the throttle body as it is at the maf?
I know on some setups on other cars, a slightly smaller pipe diameter will increase the air flow by a slight amount.

Thanks