I'm not sure I understand the question. AmpliTube models various kinds of physical gear. Darkglass make cool physical gear (I've eyed their physical pedals/preamps) but none of it is specifically modeled in AmpliTube. If you mess around with AmpliTube and gets sounds that you like -- then, OK!
If you mess around with the Darkglass pedals, amps, or plugins and get sounds that you like -- then, OK!