|Funny, my son stayed around the 95% mark for height and 75% for weight and yet I always had the reverse problem... In order to get pants that would accommodate his big bum, I have to go one size larger and then roll the cuffs so he doesn't trip all over himself.
You may want to try other types of clothing, like dresses with baby legs, leggings, or overalls. And of course try different brands of pants. It seems that some babies just never really fit well in certain types of clothing. With our son, overalls never worked: unless he was completely swimming in overalls way too big for him, he ended up with the crutch too tight and the buttons popping open. I just gave up on them...
Keep looking and you'll find something that works for you!