If the "SPD-SL" PD-R540's are properly fitted they will work just fine. I started out at 213 pounds and now am at 189 pounds after putting in 5000 miles in the last year using those exact shoe and pedal combo. What kind of discomfort are you feeling? I have ridden up to 790 miles in a month without foot discomfort. What about your overall fit, saddle, so you mash?,spin?. Maybe you just need time on the bike to get back to being comfortable again. I have not tried more expensive shoes or pedals as i have no need to change since i am not racing. I have put up to 4 hours riding time without any foot issues with this combo. Hope this helps.