lolz compressor is slow, yes. However you can speed up the process by using some options for it, for example utilize all your cpu cores.
Example
12 = number of cpu threads. If you have more or less cpu threads, change the number.
As for the installer, you have several choices here. There are some installers which are compatible with diskspangui. You can find supported installers in the diskspangui topic, I think it is the second or third post in the topic. However you can also use diskspangui itself to unpack the archives. Just copy diskspan_gui.exe in the same folder where all the created archives are and run it.