try one of these:
Buy Pearl CH70 Cymbal Holder | Cymbal Holders & Hardware | Musician's Friend
Buy Gibraltar Grabber Cymbal Arm | Cymbal Holders & Hardware | Musician's Friend
i have one of these:
Buy Tama MCA63EN Cymbal Attachment | Cymbal Holders & Hardware | Musician's Friend
i know the one i have works great, as all of them probably do. you can find some more, too. just look up "boom arm" on an instrument site like musicians friend if one of these doesnt sound good.
you just clamp them onto already existing cymbal stands.
hope this helps
butter