Flood Proofing External Skimmer - Advice Please

I just purchased an H&S A150 external protein skimmer which I'm pretty excited about. Since it won't fit in my sump (unless I did some extreme rearranging and ditched my refugium), I am planning on running it externally. I'm still not 100% sure how I will be feeding it, but it will likely be one of these options:
* From the overflow of my frag tank (which currently drains into the same sump as my display).
* Put a small overflow box in the frag tank which I would place a pump into to feed the skimmer.
* Feed from a pump which is in the sump which the display and frag tank both overflow into.
I've never used an external sump before and am obviously concerned about the possibility of it overflowing and causing a flood. I've flooded the people below us before and would prefer to avoid a repeat of that event!
The common approaches I've heard are:
* Place skimmer in a bucket
* Put a float switch on feed pump
* Modify collection cup to have a high drain back into sump
I don't want to put the skimmer in a large bucket for aesthetic/fiance wouldn't be please reasons. Also it wouldn't prevent a major flood. For example if the skimmer is pumping way too much water into the collection cup and it overflows the bucket it is sitting in. My current skimmer has gotten stuck and will push massive amounts of water into the collection cup which currently just goes back into the sump... it wouldn't take terribly long to overflow a bucket, so I don't like this route. Also, it would end up triggering my ATO which would be dumping gallons of fresh water into my system.
A float switch on the feed pump would work if I had the right setup I think. But I'm pretty sure I would have to be pumping from the sump (not the frag tank because it would start a siphon since it is higher than the skimmer) and I obviously couldn't use a float switch for a gravity feed from the overflow. I would also have to have the collection cup draining into another cup where the switch would be located since I don't see a way to place one in the skimmer's primary collection cup. Or is there another way to do this?
Another option that I do like the idea of is modifying the collection cup to have a high drain hole that would cause the skimmate to drain back into the sump if it reaches a certain level to avoid a flood (essentially what an in sump skimmer would do). Unfortunately I think my skimmer will be placed too far away from the sump for this to drain effectively. I don't think there would be enough pressure on the drain line for it to run far enough to get to the sump. Also I'm afraid that in the event of a major flood scenario that it wouldn't drain fast enough to keep up with an overflowing skimmer.
So, of these 3 options, I believe the float switch would be the most effective, but it would require a specific setup to work. I'm also not sure of where the float switch should actually be placed.
Does anyone have any other ideas or advice?
Thanks!