So, you are going strictly 2.1 with your loudspeaker system and not 5.1 or 7.1? If so, then you could use either a stereo integrated amplifier or stereo receiver. If you think you may upgrade to 5.1 or 7.1 in the future, then perhaps an home theater receiver might be appropriate. What is your budget?

2.1 refers to two loudspeakers and a subwoofer. 5.1 is two main speakers, a center channel speaker, two surround speakers and a subwoofer. 7.1 is two main speakers, a center channel speaker, two surround speakers, two back speakers and a subwoofer. The Marantz is a stereo integrated amplifier.

For around $2000 I'd also look at the Cambridge Audio Azur 840A v2 for $1700, the NAD M3 refurbished for $2000, the Creek Classic 5350 SE for $1700 and the Shanling A3000 hybrid tube amp for $1700.

The Musical Fidelity A5.5 integrated amp for $3000 could take you far.

A sleepers would be the Jolida JD1501A hybrid for $675 and the NAD C372 for $1000 ($820 at a discounter).

The speakers you have are fairly efficient (90dB/1W/1M) so any good amp with 80 or more wpc should work well.

If it's for a Home Theater setup you really want a HT receiver, because it will do the proper mixing for you- that is, sending the voices to a center channel (which is a must for HT), the music/effects to the sides (or surrounds later), and the bass info to your sub. A standard stereo integrated amp will bot be able to do that. It just sends all signals equally out to your speakers/sub. Look into NAD, Cambridge Audio and Denon for a good starting place for HT receivers.