Well, it doesn't look as clean and you were all concerned with that. However, I routinely solder up copper pipes to replace soft rubber lines to avoid buying the heavily overpriced molded to shape hoses. On like a Focus car with 9 hoses I've saved a solid $100 bill doing so, both mine and the Contour have virtually no rubber hose except the main upper and lower radiator hoses, all else is metal with a short rubber leg on each end. I use bulk straight heater hose that is like 1/4 the price of formed hoses. I started that process way back on Tempos and a 2.3 '74 Mustang II, the heater manifold I had soldered up way back in the '80s.
First time around it will cost about the same but the refit at around 125K miles will cost maybe $20-$25 for what was around $130 worth of hoses on the Focus cars. There's a stupid plastic 3 way manifold on the radiator of Focus that actually costs more than the copper refit, and the refit lasts forever. The plastic will break maybe 3 times over the life of the car.
I use steel brake line (cheaper than copper) on like small 5/16 or 3/8 bypass/bleed lines, the rubber chosen there is ATX oil cooler line for blowout resistance, it's priced high enough though that again using super cheap brake line makes up for it. I just use like 4" of rubber ATX line on either end and then it lasts much longer. I don't even bother to flare slightly the ends but I use double clamps at each connection.
One thing to remember, the solid lines will restrict you more in engine work, for instance the Focus has two bypasses to the plastic reservoir and when doing work on pass side like mount, or alt, or timing cover you could simply lift the reservoir and flop it over upside down to get it out of the way without disconnecting anything. With metal lines that is not so possible, they are too rigid. I compromised to make it to where I could flip tank almost as much. You look for those types of things when planning it out. As you move from car to car you mod your thinking slightly to get best all around result, all a learning process.
It ends up really not that ugly and when showing people they can't believe until looking under the hood, they they always give me the high five there. It's custom looking AND I make money doing it. I like my stuff as we called it in the '60s, SANO, or everything buttoned down and in it's place. I hate wires or harnesses flopping around, hoses, anything that can bring the car down, it's stupid to work on one then go down later for a silly reason and it virtually never happens to me.