I don't see where either of those mention mini-ITX mobo support. And mini-ITX systems hardly need 100 watts. Sorry, I was wrong - looks like miniITX can fit most cases, but it'd be lost in there - have to find something to do with all the space. Maybe put two of them in there...
Yeah, the X-QPack/Chenming 118 is a nice case, but it looks like it has a big hole in the mobo draawer right where a mini-ITX mobo would go. Look at the Antec Minuet.
It is possible that the mounting holes of the ITX mobo line up with the first four holes in ATX and micro-ATX mobos. You can go to
http://www.formfactors.org and check the measurements of your holes against the ATX/mATX spec. If they do, then you can use any mATX case. And you certainly don't need the 420W psu that comes with that. You could replace it with a PS/3 size PSU of 200W or less. But there are lots of small mATX cases with lower powered PSUs like the Enermax Venus series, the Athenatech A100 series, etc. The load your system will put on the standard PSU that comes with the Aspire/Chenming case will hardly get them into their most efficient range. Check ZipZoomFly.com as they may have the same case under the Ultra brand - maybe one of those will come sans PSU (yes they do!). Just bewaree of the low-profile, compact mATX cases as they can only accept low-profile add-on cards. The ones at least 5.5" thick can accept standard-height cards. I really like the Athenatech A100 cases and the standard PSU was decent (Sirtek or Sparkle) and it wouldn't be way overkill for your ITX system. Only problem I have with it is that the HDD area can get mighty toasty, so I always add some active cooling there - several ways to do it depending on whether you'll need to used both HDD bays or not. The nMedia 300 cases are also nice, but a bit larger to hold a full ATX mobo and ATX PSU. You could put either a full-sized ATX or a PS/3 size PSU in there - very inexpensive PSUs or you could spend a bit more and get one with active PFC, etc. and still not be spending a lot.
.b.h.
Here are the basic measurements of the first four mounting holes of the ATX spec: Across the back and front (on the square) is 6.2", front to back on the PCI slot side - 6.1", front to back on the CPU side - 5.2" with the hole near the I/O ports set back 0.9" from the other front hole. These measurements are all on-center. IOW, all the mounting holes centers should lie on a rectangle of 6.2" by 6.1", with the one hole set back 0.9". If these are the same as mini-ITX measurements, then you could use any ATX/mATX case. According to mini-ITX faq, the form factor is backward compatible with mATX and flexATX, so things are looking better for using an mATX case if you want. .bh.