Bones is definitely similar to Anderson Silva, but Anderson has thickened out over the years. Didn't he fight at 170 in the past? Even in Pride I'm sure Silva looked thinner than he is now.
With Bones' extra couple of inches and muscular upper half, I wouldn't be surprised if he ended up cutting a lot of weight.
I think he'll fight at 205 for a long while, but I think ultimately it will be decided by how his body develops. Saying that he could pass for 28 as it is, he may have done the majority of his growing.