Depends on what brand you buy. Any auto parts store will sell you the correct size filter, just ask. If you use an AC/Delco OEM filter it requires a PF47.
35mm
No, the only filter is part of the pump module in the tank.
18 gallon
32 mm
Passenger side of inner frame, generally a foot or two back from the door. use the correct size wrenches to disconnect filter, as these are nearly impossible to get off once they are rounded.
Look under the exhust manifold.
Toyota
35-40 Psi @2000 rpm.
36mm
235/75-15 is the correct OEM size.
Purolator or Wix is the best you can buy. The parts store can tell you the correct one.
33x12.5