Autozone, NAPA, and O'Reilly's all had new compressors in stock with clutches when I got mine about 6 months ago. I also bought A/C hoses too. They had the P/S hoses too. What a surprise! I got my new stuff from Autozone, because they had the best warrenty. Those retailers change suppliers often, so it's best to call around.
I would use the stock compressor and bracket, as it's a complex deal, and get the rest of the kit complete from them. Their kits come either way and they are very easy to deal with.
I like their kits because they are completely under the dash, no fan or heater box underhood. Easier to work on the engine, and much cleaner looking too.
TIMINATOR