Stand alone DVR advice.
 

I`m looking for a wee bit of advice on buying a 16 channel stand alone DVR.
The only DVR hardware/software i`ve ever really used are the Geovision PCI cards but thats as much as i know about the things.
It doesn`t need to be anything fancy but as long as it has 16 channels(bnc),networking capabilities and about 250-500G of HD space.

I was looking at the ones in Maplin`s along the road from me but as convenient as they would be i`d like second opinions first.
Camera`s are already in place.All we need to do is swap out the old Multiplex thing(it only does still images rather than Video logs & has no networking) and stick the new one in.

Any pointers much appreciated.