Electroplating Engine Bore

I'm a newbe to electroplating and was wondering if anyone could
provide some insight (and save me from reinventing the wheel) in the
following methods of electroplating an aluminium cylinder bore both
for protective reasons and also restoring a worn cylinder bore back to
spec. so don't need oversize pistons.

Cylinder Bore Protective Plating:
-Hard Anodizing, high silicon aluminium, easiest
-Electroless Nickel-Phosphorous/NiP: can do it in one step, hardness
close to chrome
-Nickel Cobalt: not sure if can get enough cobalt in nickel to be
useful?
-Nickel/Suspended Particles: trapping hard particles suspended in
solution into nickel plating
-Nitride: similar to how some metal tools are protected, not sure if
possible/practical
-Hard Chrome: tested and proven but an involved process

Plating Cylinder Bore Back to Spec., need thick deposit, these are
some metal I thought would be possible:
-copper
-nickel
-iron
-zinc
-tin: have heard of piston skirts being plated with tin for less
friction

Brock