Try to find good plating shop-most of silver plating solutions are cyanide based.If you want you can use do it yourself cyanide free solutions.
Ferrocyanide based plating solution:
40 gm silver chloride
200 gm potassium ferrocyanide
20 gm potassium carbonate
1 lit water,stainless steel anodes
Dissove ferrocyanide in boiling water,add carbonate and then add chloride(fresh,you can make it by mixing AgNO3 solution with kitchen salt solution),boil 30-180 minutes,then filter it when cold,then you may use it!
Never try to mix it with strong acids!
Phosphate based solution:
25 gm silver nitrate(or better pyrophosphate)
100 gm potassium pyrophosphate
25 gm ammonium carbonate
1 lit water
Stainless steel anodes
Aluminium must be zincated!Hope it helps and good luck!