To get that level of power, InDesign or Quark (ugh!) is the only real choice. However, if your needs aren't for the full-on pro dtp, but just something that does enough for simple newsletters and average small office/home use then there's a few alternatives - take a look at:
Multiad Creator Desktop - this is a cut-down version of a full-on pro application, and amazing value for money.
Stone Design Create - this is one of those apps that tries to do everything - vector illustration, dtp and web design. Some people swear by it.
iCalamus - descended from an early DTP app for the Amiga and Atari ST. I used it way back when on the Atari, but haven't tried it lately.
Scribus - Open source and therefore free. Powerful, but with some significant gotchas - it's dependent on XWindows and there's only PPC Mac binaries available at present. Worth a look if money is really tight, but otherwise I'd skip it.
There are a handful of others too - most notable of the rest is ReadySetGo, which is a real old-time Mac DTP, but it's starting to look a tad expensive. Personally (and as an Indesign CS3 user), if I was going to go for any of the above, it would be Multiad Creator Desktop - not least because there's an easy upgrade path to the full version (which is an excellent piece of software) should it be needed. A close second would be Stone's Create, which takes a bit of getting used to, but works well. If you're likely to need Illustrator-like functions as well, Create makes a lot of sense.
Hope this helps!