How to use off camera flash and wireless shutter release at the same time?

I want to use the AlienBees B800 with a Yongnuo RF-603 as a wireless shutter release AND trigger for my Nikon D90. Will this be possible since the RF603 will occupy the hot shoe slot on my camera? Where do I plug in the sync cable for the B800 on my camera?

If you want to do both with radio signals you need two sets of transmitters and receivers operating on different frequencies, one for the flash and one for the trigger. You need 4 units in total.

As a receiver for tripping the camera the RF-603 doesn't need to be fitted into the hotshoe, it just needs to have it's trigger cable plugged into the remote socket. It's just that the hotshoe is a handy place to keep the receiver when you're tripping the camera without flash.

The transmitter to sync the flash does need to mounted onto the hotshoe, the matching receiver then plugs into your Alien Bee flash. If you have a cable for the flash then you don't need the RF-603's for this part of the setup, you just connect the Alien Bee's to the hotshoe.

You do realise that you need two RF-603's one configured as a transmitter and the other as a receiver? Thought I'd better mention that.