then use the circuit using two transistors.... it will surely work for 3V and less... these circuits are even available in market pre fabricated in a PCB....
the 555 IC can sink a current of about 15mA..... the circuit i told you of can drive 2 LEDs at a time.... i bought a readymade module of it which uses 3V to do so.....
You could use either device ,I just pointed out the TLC555 can work down to 2V.
To answer your question you could hook two LED's up in parallel from the Vcc rail to the output cathode to the output of the TLC555 timer with current limiting resistors.The TLC555 can sink up to 100mA (sources 10mA). The LED's will just go on when the outputs low and off when its high.
Here is what is meant by sink, source current,and how to hook your LED 's up.About 1/4 way down the page.