newbie considering adding sump to tank

Hi folks;

I have a 55 gal, undrilled tank with a Remora HOB skimmer. I'm
considering adding a sump for all the usual benefits ... increasing
total water volume, moving ugly equipment out of tank, etc.

First thing, should I do this, or will it be more headaches than
anything else? ;-)

If so, any recommendations as to what I should use for equipment and
how I should set it all up? I've heard a lot of good things about
LifeReef's Slimline prefilter/overflow box. I'm also considering
putting a SeaSwirl on my water return. Seem reasonable?

What size tank should I use for my sump? Related to this, and this is
probably a hyperstupid question, but could I hang my Remora HOB
skimmer on the sump, rather than buying ($$$) a new in-sump skimmer?
I'm assuming I'd want to extend the tube connecting the powerhead to
the skimmer, to get it a bit lower in the sump.

Ideally the final setup would be as foolproof as possible. If, for
example, I go away on a trip and my wife is maintaining the tank, I'd
rather not come home to find her sobbing in the middle of a
sal****er-soaked room. I'm guessing float switches might come into
the equation, here.

Thanks in advance for any advice/hints/recommendations.