Check out www.venomtrading.com They recently sent out a Twitter post offering $4.00 equity trades. I don't know what they'd come down to on options, but they post $5.00 + $0.75 contract as their standard rate.
I'm told that Cobra Trading is now officially clearing Wedbush. I spoke with Dan at Cobra and he said that it is only being offered for active trading accounts however.
I received an email that Cobra Trading has recently signed a clearing agreement with Wedbush. Looks like a great option to get away from Apex. I'm going to look into the switch.
My vote would be for Cobra Trading www.cobratrading.com You get a choice of platforms (I use IQ) and they are willing to negotiate commissions depending on your volumes. Free demos too if you want to take a spin. Thumbs up for my vote.
I've had great luck with Cobra Trading and their willingness to make the calls to work and find me shares. IMO they are one of the best in this respect, however I'd just give them a call or IM them next time you get shut out at IB and want to see if someone else has shares.
I've tried Sterling at Cobra Trading. I still use Instaquote but was told I could trade significantly cheaper on Sterling. I'm not trading prop, but if you want to play with it, I know Cobra gives out free demos.
Cobra Trading hands down.....next time you can't find something hit them up on their live chat and see if they have it. Bet you find more than you do at IB.