I have the 80 lpm version as seen here 

When I first bought it many years ago, it was the only one they had. All the other products are new since then. So when I was looking to upgrade my controller to this new one, I ended up buying the combo kit as shown here. (actually the controller shown is even a newer design than the one I recently bought).

  So I have 2 of these pumps in series with one before the rads and the other after the rads. The controller varies the speed on the primary pump as needed and switches on the secondary pump (with no speed control) as needed. The switch I use for the secondary pump is meant for an electric fan.

  If I was doing it again I would likely consider one of the larger pumps. I don't know what you are using for a rad but many builders now have a single large rad under the engine and I'm not sure how or if that would have any effect on flow ability.

  I should mention that one recent change that I made was with my rads. I'm one of those guys still using a set of old ford pick-up evaporator cores on either side of my prop spinner. I previously had them plumbed in parallel with the thought that they may be less restrictive, but the problem with that is you can never ensure equal flow through both and the required plumbing was not really my favorite part of the install. So I have now converted it to a series configuration so all flow must go through both. It is more restrictive but I'm ensured a far greater delta T and the plumbing is much, much nicer. I installed a Mocal oil/water heat exchanger which is what prompted this change, so I'm quite happy with it now. 

  Ground running so far it seems better than it was before. But I'll wait until after full flight testing before confirming that series is better than parallel.

Todd