I used to think aluminum spinners were the way to go. After some noseovers at full throttle on takeoff and a couple of crash landings, I'm now a fan of Higley prop nuts or the Dubro spinner nuts. 3" aluminum spinners are expensive and I destroyed 3 or 4 of them. In every case, the only damage to the plane was the broken prop and cracked spinner I bought a pink Miller insert for my Tower starter and it works great
http://www2.towerhobbies.com/cgi-bin...?&I=LXBC75&P=0
The end they should show in the photo has a hole that tapers from 3/4" to 1/2". It grabs the small nuts really well and also works with big spinners if you want.