Listen to
photolady! Allow me to write my personal list of computer equipment, from the most important to the least:
1) Power Supply Unit (PSU). Wattage is not everything, it is the quality of voltage that counts
2) Cooling
3) Motherboard
4) RAM
5) HDD (reliability >>>> speed)
6) Graphics card
7) Everything else (CPU etc.)
Generally, I always build my own PC, mixing and matching the very best components. Rock solid
. Companies like Dell or HP select the cheapest "invisible" components (PSU, motherboard, cooling etc.) and concentrate on CPU and other "medial" ones. The result - superpowerful CPU coupled with inadequate PSU and motherboard without any free slots.
Both of computers you have shown do not have any PSU specifications (manufacturer, model number) available. Why?
.
Take a look at
Looking for an Image Processing Computer - a similar problem. I am all in favour of what "Rson" said although he really should have worded his answer a bit differently.
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EDIT: I have forgotten about the monitor. For photography - a good one + hardware calibrator is essential. You did not write anything about that so I assume you know what you're doing
. From my experience - the better monitor, the easier it is to calibrate. You will need a photography-specialised unit with good uniformity and access to hardware LUT (remember about software for your calibrator or, if you do not have one, get one dedicated to your monitor). This is not cheap, ofc.