To me the perfect gun would not have a silencer, but only for "tactical" reasons. Real life, PC anti-gun state, aftermath tactics that is. I live in MD, a very anti-gun state, and worse, I live in Baltimore. I can assume after even the most obviously clean self-defense situation that I'll be charged, because that is what the Baltimore prosecutor's office does. A silencer doesn't look very PC, so to a non-gun (and possibly anti-gun) Baltimore City jury, it will not bode well for me to have used one. I am in the market for electronic hearing protection (which will give the added advantage of amplified sounds when not shooting) and in the meantime I'll risk some hearing damage over an increased chance of ending up in prison.
That said, my ideal/perfect home defense guns aren't necessarily what I use. I carry at home, but I live in MD and I'm not self-employed or overly politically connected so I cannot carry outside my home. So, it is often a smaller gun that gets the call most of the time (my Taurus 85, one of my Rossi 461s, or my SIG P290RS). However, my "ideal" HD gun, also my nightstand gun, sometimes gets carried around the apartment.
For me, an 8 shot (or better) full size or larger compact sized .45ACP or a 6-shot N-frame .45LC are the perfect HD gun. Plenty of power (by handgun standards) and it gets it from a big slow bullet instead of velocity so it is less likely to overpenetrate and go through your attacker. I used to go with a 1911 or my S&W 1911SC, but I now prefer DA/SA or DAO with no manual safety to worry about so I use a S&W 625MG in .45LC and a .45ACP SIG P250 Compact.
As for the tactical light, I prefer one that is not weapon mounted (unless using a long-gun) so that I don't have to cover what I'm shining my light on with the muzzle until I'm sure of my target. Though, for now, I can see the utility for some limited and temporary situations. I broke my wrist about a month ago so with the case on my left (non-shooting) arm I only have real use of one hand which makes handling both the gun and the flashlight impossible. If it doesn't come off this week (it may come off when I go to the doctor on Wednesday) I may look for a cheap weapon mounted light to use until the cast comes off.