Thanks for the reply, scoobiedoobie. I too, doubt that ZIP or RAR would be a convenient solution for the reasons you mentioned. The main reason being that the ISO decompresses, when written, to an installer disc (it's a very large program).
It looks that because of this, my only choice would be to burn it to a DL layer, unless someone else has other ideas. Or perhaps just mount the image with Daemon Tools, install from there, and simply save the ISO to a hard disk somewhere, which would be a much more cost efficient solution than burning it to a DL disc.