You got so many options man- the 15-22 is the like best modular versatile tactical blacktikal accessorizable delta force-able .22LR there is- and depending on what you want to do with it yo ucan!
I didn't want a 3-9 on mine ( and certainloy not some of the 25-300x I see on the pictures of it, I mean, do you need to see 25x-300x when no matter what, even holding the rifle 45 degrees up in the air and busting caps, it aint going that far honest man) because I have two scoped, accurized, 'sniper' and 'hunting' style .22LRs, I wanted an AR .22 for tactical blacktical special operations around my hood and at the range... thjis is for practicing my ninja flips etc.
LOL. So anyway mine is for initially I used a $70 NcStar holosight, it broke of course... now it's an Aimpoint Micro i got on sale. I am trying to save for a nice deluxe 3x Primary Arms magnifier with the move-out-the-way flippable mount. They got a 7x magnifer, it looks real interestin !
Sometimes I wish and even consider an EOTech for, it would be perfect- I just dont want the 512 base model EOTech, really would want an XPS. they're expensive tho... same thing with the Trijicon reflex's ... both are great, but like $600. my Aimpoint Micro was close to $600 lisrt when they came out but I got the sale $299 so , im happy and flappy.
you got options tho- you can get a cheap o NcStar, you can get a high quality Chinese knockoff, from a high quality company like primary arms (they also give u options, from an Aimpoint Micro clone, to Aimpoint M3/m4 clone, to a 1-4 scope, to a 3-9 scope, all them options) an d you can get magnified "Scopes " to make ur 15-22 a scoped shooter... all sorts of optinos bro.