Running without the idler pulley is not such a good idea, its there for a reason, at high rpms it keeps the belt from deflecting and resonating. Have someone rev your car to about 5 grand and stand out there and watch it.....I bet it bounces up and down like crazy!
All I did was go to a bearing supplier and buy new bearings for both my idler and tensioner pullies, they both use a very common and cheap 6203 bearing that I paid like 5 bucks for both..and then you just press the old one out and the new one in, SIMPLE.