This is pretty much the solution Pina documents. I think his may involve a homemade bracket, either way, as long as it's fixed in place and not prone to come loose due to vibration during operation.
One word of caution, make sure you adjust your voltages, both now, and especially after you get your second floppy cable, and you shouldn't have any problems. The SE PSU is robust and capable of supporting more than what you're taxing it with.
And yup, it is ugly, but that's the SE series. It was the first to cram everything everybody wanted inside a compact case. The chassis is ugly, the speaker connections are ugly, the logicboard is ugly, the fan is ugly, the knock-out PDS card connector access is ugly ... and there's no way to max out the SE's potential, even with "official" upgrades without overstuffing the thing with ribbon cables, metal brackets and logicboards. There's simply nothing elegant about it. But even the exterior design suggests this: it's a machine that means business. It takes itself seriously, and is capable of un-compromised power.