Frequency meter input stage

Hi,

Ive been trying to make myself a frequency counter for some time. I have made a few attempts, but they have usually been more like random number generators, because i cant get the input stage right. I dont have much experience with analog electronics.

I though that before wasting my time and money on building the new design, maybe some of you could check my latest design out and tell me if it is OK or what should i change. The input stage schematic is at :

My goal would be to get it read up to 100MHz or more and have input impedance of 1MOhm.

Ronald