Naaah, use small value medium wattage resistors but be aware that "Some" resistors will change by a few % in value when hot...
I forgot here is the reference... again, I thinkhttp://www.ustudy.in/node/6473. Good looking website with a LOT of high grade electronics lessons as far as I could see. I apologize for not making sense I slipped outside and hit my head on the curb...
Bob