I don't think those will have enough padding for use on a heavy bag. The gloves that marcosro posted are a very good pair for the price. (Way better than similarly priced Everlast gloves.) If you only want to get one pair of gloves, I'd recommend getting a 16oz pair of those as an "all-purpose" glove that you can use for mitwork, bagwork, and sparring. (16oz may seem big, but you won't want to use any less than 16oz for sparring.)
Alternatively, you could get "heavy bag gloves", which are lighter and have denser padding, but these would only be good for bag work. They also have less protection, so I do not recommend them over the Title training gloves that marcosro posted.
Edit: here's a link to a good pair: http://www.amazon.com/Boxing-Leather-Training-Gloves-12-Ounce/dp/B002XUJ9X4/ref=sr_1_1?ie=UTF8&qid=1421341164&sr=8-1&keywords=title+leather+training+gloves