Ok The Johnson schematic is definitely "more better" , this uses a 1k damping resistor R2, you may actually find you get better footstep response by leaving off R2.
Note the LMC6462 is a CMOS device, so won't work at more than 5v. If you can't find the esoteric voltage regulator, then you can use a micropower 5v reference chip.
If you are not constrained by power drain, then the OP27 is a reliable low noise workhorse for this sort of circuit.
R5/C5 give the first gain stage a 160Hz rolloff.
The 3rd order 150Hz filter is straight forward: R8/C8 is your simple RC rolloff, typically you would follow this passive filter with something 10x higher in impedance, and there it is 68k.
The second op-amp is a classic sallen-key filter R9/C9 with R10/C10 to which he has added some gain( x 10) by using the voltage divider R11&R13 , c11 just makes it AC coupled.
R6/C6 seem a bit superflous, you would get the same effect by making R7 from two 4M7 resistors splitting the rails.
That's a 4th order filter at 150Hz all up, so he must be expecting a lot of high frequency noise.
If you are using the geophone on a hard surface (i.e. not pushed into dirt) then it can rattle a bit, best to use plasticine, or blu-tak (poster adhesive), or a cork or rubber gasket to attach to a floor.
Note that all floors have various structural modes, so moving the sensor a foot in any direction can make a big difference in its response to unwanted noise vs desired signal.
You can usually feel the structural modes with your hands.
If you put it outside in the dirt , stay at least 10feet away from trees, they put a lot of siesmic noise into the ground when the branches hit in a strong wind (shrubs are OK).