Counter and Latch in one chip or Codec and Latch in one chip

I am going to make a project, it's going to be a frecuency counter from a phisiology signal (ECG), it's going to be introduce in a 555 timer IC, then the out signal is going to enter into a counter (LS 7490), after that I use a codec (LS 7447) to connect a seven-segment display to show the frecuency, I do this twice because I want it to count from 0 to 99. I have to save the number so I need a latch, I don't know which chip will be useful, but my teacher sugest to use a chip that contains the counter and the latch or a chip that contains the codec and the latch , i have been looking but i can't find anyone of those. I have a big problem because I need all the circuit to be TTL and to use low frecuencies . Can anybody help me??