Brew stand

Here is a quick drawing of what our stand will look like. I decided to go with a 2 tier system, to eliminate the need for 2 pumps if I want to do a fly sparge. I kind of modeled the stand idea from this post.

I think I will use casters so I can easily move the stand when need. I will remove the height of the casters from the height of the stand, because I am already pushing the upper limits of the height that I want to go. The bottom height has to be that tall to fit the fermentation vessel. The top tier has to be able to transfer into the boil kettle so that height can't change.

Do you think the height will be an issue? My worry at this point is the base won't be wide enough, and the stand will be unstable. Will the use of casters add to this problem? The use of angle iron will allow me to make quick modifications if one idea doesn't work.