Before you purchase IDR, scan the fora for all the problems others have had trying to get it to work
I'd prefer to do it the old fashioned way, where I know EXACTLY what is happening and what went wrong if anything does.
The difference in install time isn't that great if you slipstrean SPs and do the initial install at the appropriate Service Pack, then do a network restore of the OS and User Data, then any Database restores (which must be done with IDR anyway) and you're done.