You do need big power for your Paradigm Reference Studio 100 v5.
With the Paradigm Reference Studio 100 v5, you need a big amp, no question about this. There is no receiver that can do them full justice, trust me, I know.
Your two receivers are much underpowered for your 100s.
What you honestly need is something like an Emotiva XPA-2 mated with a receiver that has preouts, like a Denon AVR-2809ci or an Onkyo TX-SR706, or a Marantz SR6003 or a Pioneer Elite SC-05 or a Yamaha RX-V1900, just to name a few good ones for your particular situation.
If you want to spend less for an appropriate receiver, look at the older models from Denon AVR-2808ci, Onkyo TX-SR705, Marantz SR7001, SR6001, SR5003 (newer) or SR5002, Pioneer Elite VSX-03TXH, VSX-01TXH or Pioneer VSX-1018AH-K, and Yamaha RX-V863, RX-V663, RX-V861 or RX-V661.
But if you want to go Receiver only, without an external amp like the XPA-2 (which I highly recommend for your 100s), get a least something like an Onkyo TX-NR906 or TX-SR876 (also other older models, TX-NR905, TX-SR875 or TX-SR805). The Yamaha RX-Z7 or the RX-V3900 might do it, but not so sure about this. There is also the Denon AVR-4308ci.
But the Denon AVR-5308ci and Yamaha RX-Z11 will surely be up to the task.
* The main important thing here, is that your Studio 100 v5 will never get to their full potential until you give them the appropriate amplification, period.
If I was you and money was important, I'll get an Emotiva XPA-2 with an Onkyo TX-SR705 or a Marantz SR7001 or a Denon AVR-2808ci.
Bob