That 90mm will fly fine at 5000ft elevation.I have been flying RC for 40 years mostly large scale aerobatic planes with gas engines.Last year I got into EDF's and I love it.I have a Freewing 90mm Stinger,80mm Avanti and a 70mm Yak.All fly well at my 4800 ft elevation.The Avanti is a great first EDF jet-almost flys itself.Only drawback is the 3.5 minute flight times.Just remember at your elevation your sink rate is high and with a EDF you must fly it to the ground.
As far as the Madsad I am 6'4" with a 32inch inseam on the stock seat.I have the 15" screen and set to the middle I just look over the top and it works GREAT.Best windscreen I have been behind in 50 years of riding.