The new URA checklist is bloody brilliant!
As for the IAS disagree just do it by memory and go straight for memory items for URA.
Set pitch and thrust and tell ATC you have unreliable airspeed and are unable to maintain altitude. Go to the flight with unreliable airspeed tables, set pitch and thrust for phase of flight and WAIT for speed to stabilise. Once the aircraft is level you know you are on speed. Now we cross check the indications but NOT with each other, with the figures quoted in the tables. This is very important as the cross check should always be done with a control figure rather than any number of faulty indications. Hey presto safe flight.
I have tried this in the sim at all edges of the envelope and the memory items are perfect at keeping you safe while you dig out the QRH!