A few tips:
1 - You said the rails are fully supported on a concrete floor, so I don't see where a bending analysis is even required.
2 - The bending diagram you referenced is for a beam supported at each, and only at each end.
3 - The angle iron/v-groove caster approach is a very common arrangement. We have several in our plant. However, in my experience it is not wise to have angle iron guiding the casters on both sides. The vertices of the two parallel rails will never be at the exact same separation as the vertices of the two opposing casters. Thus leading to uneven operation and accelerated wear.
There are two solutions. If you insist on having angle iron on both sides you should allow the caster wheels on one side to "float" on their axles thus allowing them to find their own center.
My preferred solution is to simply have a flat rail on one side. You can use the same wheels all around. Those on one side ride the v-rail. They provide the support and guidance you need. Those on the other side ride the flat rail and simply provide support. If you do this you have to account for the fact that the support rail on the flat side must be slightly higher than the support rail on the v-side. Refer to the attached image.