A lot of mATX cases can take a full-size PSU.
I'm thinking of getting the
Thermaltake LanBox VF1000BWS and a
OCZ GameXStream 700W PSU.
In some cases, it's actually better not to get a modular PSU because the additional cables sticking out of the unit will get in the way of the optical drive. With a non-modular unit, they all come out of the same spot and you can easily zip-tie them. With the Lanbox, the sides are non-removable and you can get one of those adhesive reusable clips, stick it to the side in front of the PSU, and open/close it when you need to change the wiring.
The LanBox looks like the best uATX case out there. It comes in black and silver, windowed or plain. The silver ones are aluminum, and the black ones are steel. It can even fit an 8800GTS (most likely a GTX if you don't use the hard drive cage) and a Thermaltake Blue Orb cooler. That's how awesome this case is, and if I do go uATX for my next build this is the case I'm getting.