When trying to decide between the wire type crates or plastic there a few things you should consider.
The wire crates have some basic features that make them the better choice in most cases.
The best style is a fully collapsible wire crate that folds down like a briefcase. There are others that are in many pieces that have to be put together with long metal pins in each corner. All four sides, the top and the bottom are all separate panels. This type of crate is much more difficult to put together than the all in one folding style. While folded they are very easy to store or travel with. The plastic style crates come apart in two halves that are more difficult to store or travel with.
The collapsible metal crates have plastic or metal trays that pull out of the bottom so that they clean up very easily when your puppy soils the bottom. The plastic molded style has no tray at all - which makes cleaning puppy accidents quite a chore!
Some manufacturers also include a metal partition with the collapsible metal crates that will divide the crate into a smaller size for the puppy when you first bring him home. As he grows you can give him more and more room in the crate until he has access to the entire thing. This is a great feature that allows you to purchase only one crate instead of replacing the smaller ones as they grow.
Some puppies do like the "Den Like" feel of the more enclosed plastic style crates..... but on the other hand many puppies love to be able to see what is going on around them with the metal crates. If you have a puppy who prefers the enclosed crates but you have a wire crate you can cover it with a blanket and have the best of both worlds! (You should take caution that some puppies may pull the blanket through the bars and chew on it!)
In short: the majority of breeders do typically recommend the metal fully collapsible crates with a divider.