You can use Bluetooth speakers, but I'd read that the sound quality suffers. I went with WiFi-connected speakers. There are at least two ways to do this:
(1) Buy Airplay compatible powered speakers, which have WiFi (and sometimes Ethernet) connection built in to them. (The
Bose SoundTouch Portable Wi-Fi® music system appears to fall into this category.)
(2) Buy an Airport
Express, which has an audio out jack that you connect to any stereo system, boom box, or powered speakers that have an AUX input. (Apple refurb at $75 is a good deal on these.)
You can use some of (1) and some of (2) in your house. I've got an Express/stereo setup in my living room, an Express/mini-amp/speakers in my bedroom, and a
Boston Acoustics MC200Air Wireless Speaker System for AirPlay in my kitchen.
I can have all of these playing simultaneously, and it sounds great! i "play" the music from iTunes on a Mac, and iTunes on a Windows machine, and I usually use an iPod Touch as a remote control (get Apple's Remote app). I have also played music directly from the iPod, just don't have much on there. An iPad should work the same -- it could be the source or the remote control or both. I think it's the Music app you use in iOS. You just select the output location(s) from a list.
The Bose system you mentioned should work with iTunes like any other Airplay system -- buried in the text they say that AirPlay is built into the system. They also have their own software which appears to allow access to more internet radio stations, and "can play music stored on your computer that is managed by iTunes® or Windows Media Player." I
think their software would be optional if you're only playing from your iPad or an iTunes library.
One important point: it's critical that there is a good, solid network connection to each speaker location. This would
have to be WiFi to the Bose unit, and either WiFi or Ethernet to an Airport Express or my Boston Acoustics unit, for example (the BA unit has an Ethernet port, rather rare for Airplay speakers). The Bose is WiFi only.
If the wireless connection, for example, is marginal, you'll hear momentary dropouts of the music, lasting from a few seconds to a minute.
Very annoying while listening to music! You might need to improve/extend your WiFi coverage to get an acceptable listening experience.
