Regardless of the limits, a good vape can be obtained at 2 ohms and 3.7v. If it doesn't produce a thick cloud, you are using the wrong atomizer. My Aspire Nautilus produces impressive clouds at 1.8 ohms and 3.3v. It's all about efficiency.
An eGO with a VV 1000mah battery should be just fine for most vaping needs. Try the Spinner and its equivalents.