Best wet/dry

Don't have familiarity with those models myself. Most won't use a wet dry, the trend is getting waste out before it is broken down into nitrate. This is why most have gone to skimming. If you stay the wet dry route be ready to do lots of water changes to keep nitrate levels below 20ppm, or use an alternate method of nitrate reduction.

I wouldn't recommend putting any live rock in the sump - it will become a detritus trap. A better choice for additional biological media would be ceramic instead. Marinepure makes an excellent media that comes in balls or blocks. You would ideally want it in such a way that it would be removable for maintenance.

Similar to what Riley said I don't like rock in a sump, unless it is in a section that water is pumped into that section after some filtration or settling. If you just have an overflow plumbed into a live rock chamber it is going to get pretty nasty in a hurry! I personally prefer to get waste where I can remove it instead of process it as in filter socks and skimming, but the great thing about the hobby is there are many right ways!