recommendation for large video storage

So this is my second arduino project and as usual Im buying stuff without much of an idea as to what im doing. I've been cruising the forums for a bit and it sounds like there isn't any simple way to interface the arduino boards (my AT Mega 2560) with large storage devices(IDE/SATA). I'm looking to build what is essentially a security system and I'd like to have at least 2, preferably 3, cameras in the 1-5 Megapixel range recording 30fps video to... something. The SD card breakout for the arduino sounds nice but at a max of 250G thats less than 24h of recording in a high compression non-HD format.

^^ That's all kind of back-story. My main question is:

-what is my best option for absolute max storage for my 2560?

-Can I attach a bunch of those SD breakouts to one 2560? It seems like I can since they just hook into the digital pins, but is it a huge hassle to handle 3 or 4 SD Breakouts?

Last note: Im planning on having the cameras overwrite old recordings, so Im not trying to save everything in perpetuity, but I would like to get more than 24h stored video.

Thanks all.

You can use the Mega to turn the cameras on and off but the Mega is not going to be reading and storing 1-5megapixel images at 30fps from even one camera.

Pete

Use a synology diskstation (or equivalent) - these are up to the task.