Yes, that type of resistor is fine. I usually use the flameproof metal film for safety, but that's just me. Here's a link to them on Mouser if you are interested (470 ohm 2 watt resistors):
CPF2470R00FKE14 Vishay/Dale Power Resistors - with Leads
Also, I'd suspect a bad JJ power tube caused the fried screen resistor if there's no evidence of arcing. Given the set of symptoms you describe, maybe the heater even shorted to plate. This could fry the screen resistor AND take out the resistors on the filament circuit. I worked on a '74 Fender Twin Reverb two months ago and it caused that EXACT same thing to happen (fried screen resistor and cooked filament resistors) inside the amp. What I'm getting at is that you should be VERY careful as you power up after doing your work if you're using the same power tubes. As Joey sagely advised above, if the power tube was bad, and you put it right back in there at start-up, you'll be right back at square one. As we all know, there are no guarantees on tubes, and they CAN be faulty right out of the box...it's happened to me, at least.