Albums with mixed formats of ALAC, mpeg, mp3, WAV

I am using the AIFF format for storing all my CDs on my MAC Book Pro computer's external hard drive. The computer is connected to the Ayre QB-9 USB DAC (and it to my Ayre AX-7e amp). I noticed that several companies offer album downloads in other formats such as alac, mpeg, mp3 and wav. Can I download these other formats and store them on my hard drive? When I select an album that has a non AIFF format, will it play through iTunes and my DAC? I also noticed that some recording companies only offer albums in 96kHZ. Can I download these albums and will they play through the Ayre QB-9? I need some help to determine if my system can handle albums stored in mixed formats (other than AIFF) and using either 44kHZ or 96kHZ. My Ayre QB-9 is set to receive 44kHZ (I think). Thanks..
iTunes will play all of those formats at any rate. It will not play FLAC but all of them can be converted to AIFF if you wish. A program called MAX will do it for you. There is a plug-in called Fluke that will let iTunes play FLAC but the last time I tried it it worked for 16/44.1 but choked on 24/96.

The Ayre will do up to 24 bit, 96K but you need to pay attention to the core audio settings which are set up in the Audio Midi application. When iTunes starts up it looks at the settings in Audio Midi and remembers that. If you launch iTunes when AM is set to 16 bit 44.1K it will convert 24/96K to 16/44.1. If you then change AM to 24/96K it will still convert it to 16/44.1 and then AM will convert it back to 24/96K, not good. To play 24/96K without conversion you need to shut down iTunes, set AM to 24/96, and then launch iTunes. iTunes will now play 24/96 natively and convert everything else like 16/44.1 to 24/96. The moral of the story is if you want to play a file without converting it then you need to change AM and relaunch iTunes every time you play a file with a different rate. If you don't want to do that then set AM to 24/96 and leave it as the conversion in iTunes is quite good but the conversion in core audio is not.

There are programs like Amarra and Pure Vinyl that use iTunes as a front end to manage the files but don't use it to play them. They can adjust Audio Midi to match the rate on the fly if you wish.