Sigma A-mount 30 1.4 or Sony E-mount 35 1.8

My purpose is indoor shots and good bokeh, I already have an EA2. For the cost, which do you suggest that I buy, the sigma or the sony? There is a sweet deal for the Sigma currently. I never had a 1.4 lens, I have an E 50 1.8 (which I love). I am not aware if there are significant differences between the 1.4 and 1.8.  thanks in advance.