That seems like a pretty large starter. How did you do your calculations?
One thing that can help is to use the "intermittent shaking" method, where you shake up the starter solution every 4-8 hours or so. This will allow you to use a smaller starter, although not as small as you could get to with a stir plate. Per Jamil's calculator, you can get by with a 3 liter starter, if you shake it intermittently.
With large starters, I prefer to make them up with DME that is not part of the recipe. The night before brewing, I crash cool the starter by putting it in the fridge. The yeast then drops out of suspension. An hour or so before pitching (like right at the start of the boil), I decant the spent beer from the yeast, and leave the starter out on the countertop to slowly warm to room temperature.
I'm not sure where you're going with "add another pound of DME to my boil?". Starters don't go in the boil.
The HBT Wiki has a decent section on making starters.