Neither.
Seriously, the London and Colle systems are "systems" and therefore don't lend to giving you a strong advantage. They mostly help you avoid tons of theory and allow you to know your way around pretty well in the opening once you learn them. I toyed with d4 systems a little myself. I found the Colle, particularly the Zukertort, more interesting and more promising that the London.
If you want some books, there's the Zuke 'Em books by David Rudel and A Killer Chess Opening Repertoire by Aaron Summerscale. They are good if you're into the whole 1.d4/opening system thing.
I have played 1.d4 2.c4 most recently as white, but do not want to have to learn all the indian defenses. I have been looking in my opening book, which covers the Colle and London System much too briefly, and online databases and I have found that, though the London doesn't block the c1 bishop in, it is less successful, giving black better chances statistically...
I don't know which would be a better choice to learn...help, please.
Thanks
DJ
p.s. I have been wondering for a long time: how do you pronounce "Maroczy"?
Thanks again