Gnome won't help you with programs lacking on the CD! If your concern is about the programs, you must create a persistent image and use (e.g) Synaptic to install whatever you want. For me, that has been a fairly easy thing to do, even though I haven't used Debian before, except for through Knoppix. Lots of "standard" programs had top be left out from the CD, but it's very easy to intall them to a persistent image.
My best advice is that you try to modify LXDE to tailor it to your needs as best you can first, then install the programs you want, and only afterwards try to change to standard Gnome.