Well... it's hard to say if you need to replace the Wavetable VCO. As a source, it doesn't have a lot of modulation inputs. Are you running the VCO through... filters, wavefolders, distortion, comb filters, etc.? Each module you place between the VCO and the reverb is an opportunity to alter your sound as well as modulate that alteration.
When you wash something in reverb, the sound basically smears. Subtle differences in timbre tend to wash away. So you might want to possibly try the same VCO and run it through two completely different signal paths (or more!) then mix between them using some very slow modulation... just an example.
Before you toss the Wavetable VCO and spend more money, maybe a picture of your current set-up would be helpful. Oh, and the 2HP reverb is pretty limited (I own one). It's good to have. But I'd want something with more parameters that can be modulated. Oh.. and have you tried placing a filter after the reverb. Even a simple band-reject filter can add some motion to your ambient sound.