Bang for the buck, id say a Directed 1100d or 1500d (same thing) will do just fine.
At one point I ran mine for 2yrs @1ohm. Pushed the amp into thermal more times then I can recall (during the summer(s) in AZ) and it still works just fine.
As far as the SAZ-1500 goes, you get what you pay for. I wouldnt mind owning one of those. Remember they are rated at 12v. Your car is usually 13.4-14.4 when its running, meaning you're getting quite a bit more then 1500rms. SO as far as $/rms watt goes and bang for the buck, id add that to the list.