I tried Doran's Ring(to be tossed later), Lichbane, Guinsoos, Merc Treads (the boots are situational imho), and Frozen Mallet, respectively. I had pretty **** good results with her, excluding the feeder kill 14-7.
Well I got Guardian's Angel last, actually, but I didn't get to use it. Could the Lichbane or Trinity Force proc be crit-ed? If it does would Phantom Dancer be viable?
Also, assuming you don't go cdr runes and masteries, I'm interested in results from Lichbane and Ghostblade together.
I 'spose Banshee's is good if you're not using Cleanse (with the build I just described was the first time I tried Exhaust and Ignite, does wonders).
I wouldn't risk trying Rylai's with the Righteous Fury, considering it's splash damage I would only assume the 15% slow.
I'm unsure on how effective the Hextech is with Kayle, but it shouldn't be a high priority for a Kayle build, and most likely by the time it is viable item it'd most likely be in-base battles, so the extra slow ability may or may not be helpful.
I like to play Kayle less in the front because shes less durable and dies faster now. I usually get kills and manage to assist pretty easy though. Make sure you team knows that if you ult a teamate they should stay unless they are outnumbered. Most people use it to run away...