I'd pick a model with adjustable mouth and with a good lever that corrects an iron skew. Vintage or new they're about the same after properly fettled, except the looks.
A mouth has to be adjustable to the point where it's completely close, or it will be hard to use it on curved surfaces or when blocking thin pieces.
Also I wish I would pass on a skew iron Irish chariot plane, it was about the size of #60 1/2, but would be quite a bit more useful for blocking purposes w\o being mechanically too complicated.