The people who caponize their birds usually have a large number of chickens that they also raise for meat. You certainly don't want to attempt caponizing a bird the sex of which is hard to identify. It's a very risky procedure, especially when the person doing it hasn't done many. Someone new to the procedure needs to practice with unwanted cockerels, not pets.
There is a personality advantage with a caponized bird, but this is more relevant in situations where there are 20, 50, or 100 chickens running around, like on a farm.
I would just leave your silkie alone and give it some unconditional lovin.' Silkie roos are normally pretty friendly and if roosters aren't allowed in your location, they are easier to rehome than roosters of most breeds.