It shouldn't be too hard to find a place which rents gear. For example, Bächli has a shop in Zurich and rents out many things
, but there may be better deals out in the small mountain towns.
Also, don't underestimate the dam. I know people who were quite active climbers leading up to their trip and turned back after a few pitches. It is long, and overhanging, and there really isn't a place to rest. One planned to bring some sort of hanging seat next time, to be able to recover better while belaying.
And finally, WTF is a "certified lead climber"? The Swiss gyms that I know will let anybody sign a form saying that they know how to lead, and you don't normally get to practice actually installing quick draws in the gym. Personally, I'd only go out with somebody who I trust both technically and attitude wise, and excepting IFMGA level credentials (which of course, are a whole nother level), I don't think any certification would be part of that judgement.