Form factor usually refers to the motherboards. I'm guessing that they both are mATX.
The cases look like standard mini-towers so the standard PSU's should fit. Graphics cards? Don't know. The physically shorter cards should fit.
looks can be deceiving. I had a gate way PC once, case looked like a mid tower atx case you could get anywhere, but the PSU slot could only fit proprietary PSU's. Mind you that was ten years ago, maybe now adays they stick with ATX with the exception of slim models.
yeah I could nearly bet its a mATX case. Strangely enough I'm using an old Compaq one at the mo and it's fine for my Q6600 and ATI HD 4870, but the powersupply is a bit too cramped in there (originally it was a 300w and now I've a 750w). But I've had my share of mATX cases that wont fit the full length Graphics card or powersupply