I'd recommend a 'trigger'-style capo, for its consistent efficiency, ease of use and solidity. Here's four, from Amazon; cheap enough to try out, with a slightly more expensive option...
Amazon Trigger Capos ...
Our Eldest uses these (or ones like 'em...), fitting one for the intro of 'Under The Bridge' before whipping it off for the rest of the song. Our Second Guitar uses one, too, to match the singer's choice of key. They all have rubber 'jaws', and do no harm at all to the guitar neck.
Hope this helps.
Edit : Note the difference in shape between a 'flat' one (for nylon, classical, flamenco guitars with flat fingerboard...) and 'curved' (for electric, archtop, radiused fingerboards...) and buy accordingly. The rubber jaw will accommodate any slight difference in curveture, normally.