Connecting Audio

imhififan recommended not a good idea

It's not advisable because the two sets of outputs on the RX-1070 are paralleled, if the preamp mute its output by shorting the output to ground while the preamp is power off, so use the 2nd set of output on the RX-1070 as the input of SX-950 pre-out will not work.

If both units are power on then there's a possibility of damaging one or both units!  

My suggestion is to connect both units pre-out through a source switcher to the power amp input.

This person recommended going with Audio Source Signal Selector. I've done some research and this one seems capable of what I need. 

I would only be using 1 set of speakers.

Just confirming if this would work before purchasing the Unit 

Thank-You

Pioneer Receiver SX950 would plug into (AMP A. IN) Audio Source Signal Selector

The Second Unit is a Rotel AMP & Pre-AMP which I'm using together now.

(AMP B IN) on Audio Source Signal Selector plug my Rotel AMP?

1 set of Speakers in the Audio Source Signal Selector (Speakers OUT)  

Does this seem right?

Yes.

I found this one I think might work for me using two Audio Units using 1 set of Speakers. Before I purchase the Unit. Do you think this one will work?

I believe the Solupeak P2 will work. However, I suggest you open the cover of the unit to make sure it using a 4PDT switch and the ground is switching with the positive posts. 

And something like the picture below which is using DPDT switch should be avioded ( please note those ground are all connected together), that is OK for two pairs of speaker sharing one amplifier but not the other way round.

@rpaudio 

There's nothing to stop you running an interconnect from the Pioneer pre out to a line input on the Rotel preamp - so the Rotel pre/power will pick up any one signals from the Pioneer.

Question is - why do you need to use both ?