For what you want I wouldn't buy anything under £150 because I don't think you're getting the right product. Spending another £10/£20 makes a significant difference to the performance.
Here's a quick round-up
Under £150
Monitor Audio Monitor Audio CT165 T2 (£135). Nice tweeters, excellent construction. Bit bass-shy though (60Hz) and at 6 Ohms it need a bit more amp muscle to start working. Verdict 3/5
Q Acoustics P160C ST (£130) Completely and utterly outclassed by the Monitor Audio. Low efficiency. Very bass-light. Under-spec'd tweeters. End of story. Verdict 1/5
Over £150
Kinetik E160 ICS (£159) - Good spec, Decent efficiency, 8 Ohm impedance, composite woofer and pivoting 1" Hi-Fi silk dome tweeters, joint best bass extension of the group (45Hz), low power requirements, 5 year warranty. Verdict 4.5/5
BluCube CXCL 650 (£165) - Great spec. Decent efficiency, 8 Ohm impedance, Kevlar woofer and pivoting 3/4" titanium tweeters*, joint best bass extension of the group (45Hz), low power requirements, 5 year warranty. *Would be nice to have 1" tweeters. Verdict 5/5
Q Acoustics QI65CP St (£165) Once again, completely outclassed by lower cost alternatives. Low efficiency. Very bass-light. Under-spec'd tweeters. Verdict 1/5
Yamaha NS-ICS600 (£179) - Limited spec details and poor bass response. Not a bad speaker but nothing here to justify the extra cost compared to the Monitor Audio at £135. Verdict 2/5
Monitor Audio CT180-T2 (£180) - Nice tweeters, biggest woofer in the group (8") but oddly not the best bass extension. 6 Ohms impedance means it need a bit more amp muscle to start working. Verdict 4/5
This isn't everything in the market as I'm sure there's other products out there that aren't on my radar. But it's a reasonable overview.
If it was my money then the BluCube CXCL 650 would get my vote, then the Kinetic.