Back in the day of early 90s dodges, they all ran SAE double flares and you could buy preflared lengths and unions and cobble something together.
Now with ABS they've chosen 4 different oddball MC line nuts and it's tougher.
You can buy adaptors at NAPA but they're about $9 ea and another failure point.
Best bet is to get a preflared line that has a flare for one end you need, then cut the other end off and stick the nut you already have on there and flare it.
Remembering the nut before you flare is an important step.
That nicopp stuff is apparantly the bomb, also. You sometimes want 15 feet of bulk line to get to the rear because otherwise you'd have about 3 unions in line.
Flaring an existing line with brake fluid slowly dripping on you when the car is on jack stands is about 8 out of 10 on the misery scale.
You also want to make sure all your brake bleeders aren't rusted closed, or that you have some sort of plan for that. Having a brake drum stuck on with rust so you can't get your wheel cylinder out to fix your bleeder is a multi-layered disaster.
I have never found line wrenches useful. If it doesn't go with an open end or vise grips I cut the old line and stuff a 6 point socket on the line nut. It would grab and twist the line with rust anyway, so no loss.
PS a lot of cars (early 00 W bodies) run steel fuel and EVAP lines next to the rusty brake lines so you get the joy of running five new things down the inside rocker. Those I splice nylon into. At least I can use compression fittings on those.