How many LE can be connected to one DMX Dongle?
you can have up to 512 channels and I believe 32 devices. So if you were to hook up 32 SSR4 devices (4 channels each) you would max out DMX with only 128 channels. In the case of the Express you can 32 to a single DMX for a total of 512 channels.
NOTE: If you want more then 512 channels you can add a second dongle and create a second set of 512 channels.
One thing I saw missing is a radio. In most cases you'll want to transmit your audio which will require a transmitter. I went with the one RJ recommened in another thread and I like it. It interested let me know and I'll double check what it is.
Another point to the above is wireless versus wired. Wireless will cost a little more but will help reduce the number of wires in your yard.
Its all about money. You make it and we'll give you ideas on just how to spend it. 
The 32 device limit is really for the older RS-485 chip, we did keep it at 32 devices per RS-485 as a percaution.
With wireless or splitter or LE splitter that device limit is not an issue using them and counting the total number of devices.
Cheers
Rick R.
