There's many choices when it comes to an intake replacement doing a stage 1.

Here are a few choices to help you out there. I have furnished the links for the stage 1 mostly from the manufacturers but shopping around can get you a better price on a lot of them.

Big Sucker by Arlen Ness
http://www.cyclespot.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=HS-AN18-500

Doherty Power Pac
http://www.dohertymachine.com/index.php?cPath=2&osCsid=17c80670deccab6fb18a49ac752740eb

Harley Davidson stage 1 kits for different models
http://www.waughhd.com/php-bin/ecomm4/products.php?product_id=376&prev_id=&next_id=&PHPSESSID=750dba5ff0e18403881d96be35b5fa69

K&N Engineering
http://www.knfilters.com/harley_custom.htm

Zippers Taller Filter element for 320CFM
http://www.zippersperformance.com/catalogue/showproduct.asp?cat=863&prod=2155

MORE TO COME.