I'd suggest the spectre II as well, with one caveat.
If you intend to use a shrouded barrel like the Tac Sol SBX, seriously consider the Sparrow. Its design won't ever leave you with a thread adapter stuck to the muzzle threads 6" down inside a tube, wondering how you're going to get it out. The core on the Sparrow is threaded to the muzzle directly. There is no adapter to come unscrewed. You'll maybe end up with a little FRP but it would be well worth it. (Negligible on a rifle, and if you absolutely need quiet, a little ablative media will completely eliminate it.)
Heck, you're going to end up with at least 3 22lr silencers anyway, just start off with one of each. Spectre, Sparrow, and Voodoo.