Gain is not power, and vice versa. You can’t infer what power output the 75 to 80% of volume represents, without a lot more info. What’s your source, and do you know its output level? If you have a source with low output, it’s even possible you could hit max volume before hitting the amp’s max power output.
Your Elysian 4 speakers are 89 dB per Watt (2.83 V is 2 Watts) and 4 ohms, so Solid State amplifiers that "double down" into 4 ohms may be advantageous. Your Cambridge gets reasonably close to "doubling down" and 120 Watts isn’t bad, but gosh those Elysian look so nice I bet they’d benefit a lot from an amp upgrade! The Cambridge also says "4 ohms minimum" which is usually not good news for 4 ohm nominal speakers which typically dip below 4 at certain frequencies.
Separates (power amp and preamp) will usually give you a lot more total gain to play with than an integrated amp. A tube pre and a SS power amp combination could be very nice. You should also specify a budget, your appetite for used gear, and expect many of the recommendations to be over budget :)
