The fans ok, and for your needs most of it is fine. However I’d just get a hard drive from Western Digital or Seagate, and get a better PSU fom Antec, Thermaltake or other high quality brands. Doesn’t need to be bigger than 350W as long as its got good amps.
Yes. SATA II and SATA are compatible. While SATA II allows for 3GB/s, that’s a burst rate, not sustained, so with the connectors the same, that additional headroom should be a moot point.
If you’re not overclocking, you might consider dropping the extra heatsink. The retail version of all CPU’s come with a heatsink and cooling fan combo. While, yes, you can buy better cooling, if you’re not building a silent rig or a screaming overclocker, you really ought to consider dropping the extra heatsink from your list.
Do you have a link for that Asus case? I can’t seem to find their TA-210. I can find TA-230’s and TM-230’s, but no 210’s. I want to check and make sure that case is compatible with your motherboard (ATX standard)