Which air filter?

[ViciousCycle]

For my bike has RT-1 slip-ons but is otherwise mechanically stock as far as the engine goes. It's time for a new air filter. I don't want to spend hundreds of dollars on upgrades, but maybe up to $150 would be okay.
Should I just get a stock replacement filter, or a K&N drop-in filter, or something else? Would a stage 1, or 3 or what have you make a difference on a stock bike? I'm fairly competent mechanically, if that matters.

I've been trying to sift through the available data on the web, but I'm getting lost in all the the different opinions. Thanks in advance.

 

[Lew L]

Hi,
I went a K&N( I do have them on all my bike,cars and truck). Also raised the "Y" about 1/4" and may try for a bit more this summer. I have to find the right material to do the job. I ran the bike with out the "Y" and it seemed to lose some of that great low and mid range where I spend too much time. But raising the "Y" is a good compromse. I have also shimmed the needle about 0.025" and tied the spring a few coils. If I have the carbs of I will reduce the main jets a size or two as they are a bit rich from the factory.( and I live a 5,000 ft:surprise: )