98 24 valve dodge 4x4

I own a 98 4x4 ram quad cab 2500 with an auto trans 3.55 rear untill just recently i used to get avarage fuel milage from 16.8-20.4 mpg empty on mostly highway driving. I own a small auto repair shop in florida and worked fro the dodge dealership on merrit island florida. I just started experincing a misfire at idle intermitting, sputtering sound at the exaust. it runs fine cold and smoth. i beleive it is need of new injectors, the valves were checked and adjusted.it haas 245k on it . what is the best choice for the 24 valve, I tow 15- 20,000 lbs at times with it through the mountians 4 times a year. I was looking at some stage two injectors. i dont want the egt to high. and to load the engine with extra fuel under load. what is a good comprimise? from some of you experits....