Ben did all the weight comparisons when he was building his casting rods...he should be able to help.
Although there is a focus on weight, something worth considering is that a Torzite lining is around 400 times "slippier" than SiC and around 17000 times slipper than a wire guide. (Source rodbuilding.org). The shoot you get is as friction free as you will be able to achieve with current materials.
If you add in the K-series cranked stripping guide, you get far better transition from the coils of line on the ground up into the first guide.
On a 5 weight rod purely for casting, I think I would be looking at a combinations of guides with PacBay minimas on the top half, Torzites on the bottom.
7 weight and above, Torzite all the way.