Surround speakers

Because the current satellite surround speakers (rear) are not comply with KEF R300 front speakers, I want to replace it with the following (Marketplace €70):

The compact Model 70S was designed as a rear effects speaker in surround sound applications, but could also be used as a main speaker in a dedicated sub-sat system, in particular with the matching 40B subwoofer. Using the same Uni-Q array as in the Model 90 centre speaker, uniform coverage over the listening area was assured, as was the timbre match with Reference Series main speakers.

Specifications Surround Speakers: 
Brand: KEF Reference Series Model 70S ('98)
System type: Two-way, closed box
Sensitivity: 87 dB
Nominal impedance: 6 Ohms
Amplifier requirements: 10-100 W
Frequency range: 120 Hz to 20 kHz
Maximum output: 107 dB
System: Uni-Q Drive unit with Crossover  
LF: 160 mm polypropylene coned bass/midrange unit
HF: 19 mm fluid cooled soft dome tweeter
Dimensions (HxWxD): 253x170x119 mm
Weight: 3.1 kg, Volume: 2.5 litres

        

Specifications Center Speaker: 
Brand: KEF Reference Series Model 100 
System type: Two-way Reflex
Sensitivity: 90 dB
Nominal impedance: 6 Ohms
Amplifier requirements: 25-175 W
Frequency range: 70 Hz to 20 kHz
Maximum output: 111 dB
System: Uni-Q Drive unit with Crossover SP2227
LF: 160 mm polypropylene coned bass/midrange unit
HF: 25 mm fluid cooled soft dome tweeter
Dimensions (HxWxD): 174x460x169 mm
Weight: 5,2 kg