I'd say a dedicated LFO like that would be a waste of your money, as something much better like an osc that goes into LFO speeds with more waveforms would be not much more and provide much more flexibility. Think a
So if you really need an output module. Most audio interfaces and external mixers can handle modular level outputs just fine. That's money that could be spent more wisely in a small system.
Also, the uzeus does not have headers to power Analogue System modules, so you'll need to track down an adapter somehow.
I also wouldn't miss out on getting the Quadra expander either. You'll be able to make ads right envelopes with it, as well as make square wave modulation. You will also be able to create some more complex modulation functions like quadrature chains, cross patching, etc.
And lastly, keep in mind that the moddemix, while interesting, is not always the best VCA in a small system. It's very quirky and distorts/colors any sound going through it. Like, a sine will never come through it as a sine.