How timely.... since my advice earlier today did not help the other person (different question than I answered), here is your source of good current information:
Click HERE.
Basically you'll get what you need with two fast quad cores (I'd get the E5345 version I recommended) plus the SSD I recommended. That is a SATA generation II SSD, as is the xw8400 workstation. The Intel Toolbox free SSD software lets you fine tune that nicely.
I'm running 16GB of RAM and both W7Pro64 and W10Pro64 on these.
The memory controller is such that if you have a slow processor your memory will slow down to match that. Thus, you want to let the memory run at its fastest 1333MHz FSB speed by getting a processor that can provide that too.
And, filling your memory slots with identical memory sizes is important to utilize the full speed/bandwidth available to you. If you mix and match sizes and types of memory then there can be issues as I mentioned in the other posts. Our favorite HP engineer emphasizes this over other improvements.
So, you want to do all three I have mentioned...... that still can be a snappy workstation!