Here's a top tip - if you think a niche has potential, build a couple of HubPages, or a Squidoo Lens or two, or a Wizzley Wizz. If the pages get visitors and (better still), make a few dollars, then it's worth building them out into a separate website.
For most of these keywords, if I thought I had a chance of ranking for them then I'd build a 50 page website. I'd look for a domain name like rentadancefloor.com or hireamagician.net. If the niche was quite competitive and all the good names were taken, then I'd use "the" or "center" as a prefix or suffix respectively. Even if clownhire.com is taken then I'm sure you could find something like theclownhirecenter.com.
As far as building the website, I'd use a decent, paid for, Wordpress theme. I'd write all the content myself, and add any photos of the items I'd actually taken.
I'd also pull in some content from other sites, especially videos from YouTube.
I'd not shy away from linking to sites in the niche. Don't worry, because although you'll lose a few visitors who click on the links, it's more than compensated by search engines rewarding you for giving your visitors links to good resources.
I'd also approach businesses with websites in this niche and ask for content (articles, photos) in exchange for links. Few people actually do this with their niche sites, but it can work very well indeed, especially once your site is ranking well and pulling in visitors.