Replacing old bathroom fixtures in a 100 yr old house. Has old 2 wire bx and I want it on its own circuit. The supply comes in from another room to the ceiling box where it goes to another room and to the wall switch then from there it goes to the medicine cabinet. I want to have this room on its own circuit breaker and I know how that's done did it before without incident. Question is do I need to use bx or can I use romex for this? 3 wire with ground? I would like to have the ceiling light operated by a wall switch, also a medicine cabinet light and a outlet (gcfi) then it would be great if I could add a heat light in the shower stall do I need 240 for that and what's the best brand for this application around water? Keep in mind room is ripped out to the studs and ready for installing anything. Live in new jesey with inspector coming must be correct and that's the way I want it done right

You can use romex, 2 conductor plus ground = 3 wires total. 14/2 romex would probably be fine for your bathroom lights.

The gfci however will need it's own 20 amp circuit, 12/2 romex.

I personally don't know of a heat light for a shower stall, someone else here might or you can shop around and look to see what voltage and amperage you will need to hook it up.

Nutone and Broan are two manufacturers that come to mind that will have recessed heat lamp fixtures rated for showers. Check the instructions, most will require the fixture to be GFI protected if installed in a shower. These are all 120 volts.

So this light can be on the 20 amp GFI circuit for this bathroomif the circuit is for this bathroom. Otherwise the heat lamp will need it's own GFI device.

Do it in romex. 12-3wg pulls easier than 12-2 and why not pull 2 circuits where possible? I know that MC cable comes as 12-4wg so you can have a 220v and a 120v circuit with the same cable. MC is harder to pull (wound metal jacket) but you could just do MC from panel to (accessible) junction box and change to romex there. Since you are down to the studs and want it done right have you considered a heated tile floor? Very nice in winter. I suppose you could do this in 14ga if the loads are right but I like bigger wire for less voltage drop, heat in conductors, and more capacity for other stuff you forgot you wanted.

The way I feel about this issue is...
Do it in conduit if you are already down to the studs.
Conduit will protect the wireing more than plain Romex.
I prefer conduit over anything if at all possible.
You can always pull in more wire for added circuts later if need be.
Just my humble opinion,
C'ya

Yeah, I prefer conduit too, but the fact is that this guy probably doesn't own a bender or the bending skills. Galvanized flex is a bummer to push a steel/glas through when bent tight or more than a couple of bends, and Smurf tube (ENT) doesn't bend tight without breaking (besides the fact that it is now unacceptable for other than low voltage-at least where I am) and doing any of these in 100 year old WOOD FRAMING just plain sucks. It's a residential bathroom not a packing house. Drill your holes right, use nail plates in the appropriate places, and be done with it. Don't forget to leave room for the backing for your towelbars, cabinets, mirrors, anything you plan to mount to the wall or ceiling...