Yup, that's called a PS3 size (same width and height as std ATX but much less deep) not a uATX size. Fortron has a 200W unit - FSP200-60SPV-D. You could use Froogle to search on "PS3 power supply" and see what pops up - but I don't recall seeing higher than 200W in that size.
. I found a HighPower 250W. PS3 that's going for around $50. All the rest are 200W units for under $30. HighPower is decent, Enlight (and other brands) rebadge their PSUs.
.bh.
There's the :sun: !