Dave43 is right, so I will go ahead and be the fourth to tell you that your receiver is a poor match for these fine loudspeakers.
Not to say you shouldn't follow Cmalak's advice and get the Thiels of your choice and then move to better amplification as your budget allows. Just make sure that your Marantz receiver is capable of driving <4ohm loads, otherwise you will soon be listening to the wonderful sound of silence.
Better yet, why don't you pick up a pair of used Thiel 2 2's for about $800 (IMO these sound better than any of the models you mention) and use the extra funds to buy an amp that will do the job well.
Good luck.
Not to say you shouldn't follow Cmalak's advice and get the Thiels of your choice and then move to better amplification as your budget allows. Just make sure that your Marantz receiver is capable of driving <4ohm loads, otherwise you will soon be listening to the wonderful sound of silence.
Better yet, why don't you pick up a pair of used Thiel 2 2's for about $800 (IMO these sound better than any of the models you mention) and use the extra funds to buy an amp that will do the job well.
Good luck.