Probably any modern namebrand card will work fine
Speed was more of an issue 4-5+ years ago - most cards on the market are more then adequate speed wise
Only buy from BH, Adorama, Amazon - make sure the seller is actually the site you are buying from - Amazon for example is a marketplace with many sellers so you need to look at the seller listed before you buy.
There are MANY fake cards on the market so never buy from eBay, or any other unknown seller.
You may also want to verify the recorder can handle larger cards - some recorders (i.e. the hd-p2 for example - only supports up to 8GB cards w/o firmware update) need firmware upgrades to support larger cards and/or won't support them at all