I personally dont like ds VC on WiiU, it does detract quite a bit. And the blown up graphics on the tv can look horrible.
There are some really good uses of the DS tech that are completely lost on the WiiU VC versions. If you can i'd recommend getting PH/ST on the DS if you have one and can find them. Theyre not very good games to begin with though.
But thats just me. Them being on VC may not bother you and you might enjoy the games. Hunt out some reviews of the VC versions. A site called NintendoLife are good at reviewing VC games.