I use 3/4 inch stress resistant steel...have a local machine shop spin them for me. They will flex instead of bending and with the way we designed in a taper, the bend point is moved way out to the end of the tie-rod so if for some reason you hit something hard enough to bend one, the bend is out on the end and doesn't turn the tie-rod into a horse shoe...you probably will not even know you bent it until you go to spin it out and you notice a small wobble in the turn...The one bad, you have to powder coat them or they will rust quickly...and they are not light weight...I figure the front end is too light anyway on the Pilot so it helps putting weight low and forward...
For ends, I have used stock Honda EX400 ends...cheap, readily available at any Honda shop...I have yet to have one fail on me and I have abused/tested the limits of tie-rods/ends more than most...
Aluminum is nice...light, strong and doesn't rust...LW can tell you all about them...so you do have options if you have a machine shop available...