I can't say that I could suggest any cheap alternatives to those that you have. Honestly if you drill the airhole a little larger and use some sandpaper they should fit fine as well as look fine. You may have to give them a serious buffing but I know that is what alot of guys do. The only other ones that I would suggest are the forever stems by Walker Briar Works. However, they are made specifically for cobs so I don't know if they would fit the pipes you are thinking of putting them on.
http://www.walkerbriarworks.com/html/_forever__stems.html