Your assessment of my recommendations is accurate. I was pushed for time when I made them, so let me explain a few of my choices:
PSU - is a great PSU and it is WAAAY overkill for the rest of the system, however, it was the same (sale) price as the PSU I was going to recommend (Corsair 550VX) and excels in every way.
Mobo - is adequate for the hardware (and I own one!
) with minimal expense. The EP45-UD3L I referenced in my post is a great alternative for not a lot more and is also a proven overclocker if that appeals to you.
CPU - I like the e5200 because it is solid as is and overclocks easily with a board like the EP45-UD3L even on a stock cooler, although getting an aftermarket cooler can be helpful when overclocking. It is inferior to (and half the price of) the e7600 in your original post, however, at $150, I'd find it hard not to go with a quad core like the q8200 for $160.
It can be hard to design a system with vague information and get it just right. I'm glad you liked some of the recommendations and I hope it gives you a place to start and modify for your specific purposes. If you need any more assistance, I'd be glad to help.