> I quickly abandoned that idea when I saw that rack mount makes things cost significantly more.
Second hand (but perfectly usable) parts. Expect more second hand enterprise items to get to the market if the economy doesn't start to boom soon. Second hand enterprise gear is usually perfectly fine in terms of longevity. Mind the noise.
Get a 3d printer, print some rack adapters yourself. There's a surprising array of adapters for all sorts of devices and they work just fine for stuff that's not too heavy(like most home networking gear).
If the rack itself is too expensive, you can do an Ikea Lack rack. Full size racks are easy to find (relatively, location dependent). Haven't had much luck with network racks (which was the largest my wife was comfortable with). So I bought the rack new. Still managed to fit the whole networking gear stack(none of which is racked atm, they are sitting on a rack shelf) and a ITX server (Node202, which I used as my workstation in the past, fit perfectly).
You don't really want fiber optic unless you are connecting two different buildings that do not share ground. Inside the same house, ethernet works just fine. Fiber is finnicky, most home contractors don't know how to deal with it, and transceivers are expensive. More expensive than 10G usually.