Quantity   Component name
20 × 10 MOhm resistor 0805 or larger
1 × 100 KOhm resistor
2 × coin I meant money, but coin cells will do =)
1 × blank PCB
1 × metal cup to serve as a shield
1 × potting compound
1 × coaxial cable
99999 × capacitors for compensation a variable one might help