I use about 45 to 50 percent of my raw max on speed day with abut 50 lbs of chain on top of that. I alternate 3 weeks of green bands plus chains, 3 weeks of light bands plus chains, and 3 weeks of just chains.
I think the key to speed day, is not so much what percentage of your max you use, although that is important, but it is important that you use a weight that you can perform 3 reps with one breath in under 3 seconds. I have my spotter time me from the moment the bar starts down to the moment I lock out the third rep and lately it has averaged about 2.65 seconds.
Don't get wrapped up in putting up heavy weights on speed day. I worked up to where I could bench 245 for 8 sets of 3, and I was able to do all the reps, and still had some left in the tank, but my speed was terrible. I have since dropped down to 185 to 205 plus chains and sometimes bands, and the speed is a lot better.
Regarding singles, yes, if I feel good, I will take one or two singles after speed work. I used to go pretty heavy on these every week, doing a lot of reps with a shirt, but that wore me down pretty quick. Now I only do shirt work once a month or so, unless I am breaking in a new shirt. I will usually take one single at around 315 to 325, and then one in the 350+ range just to make sure I am still moving the bar at a good pace. But I only do these when I am feeling pretty good, maybe every other workout or so.
B