I have not seen them... I shall look out for them. Current price for 1 meter is £5.99 and 2m is £7.99 on Amazon.
If they are too bright, put a resistor between the power source and the strip. The higher resistance, the dimmer the light output.
If the colour is too bright and you want a more 'yellow' colour, Sharpies are your friend they are very effective!
My solution to flicker is a simple circuit using a bridge rectifier, 5v1 zenner diode, a couple of resistors and a 5v5 dual layer or super capacitor rated at anything between 0.47 to 2.5 F. On DC you can stop at a signal or station and the lights stay on. the higher the capacitance, the longer they stay on.