Quick answer: The Diamond X700HNA is what you should get of the two. It weighs less and will cost much less to install. Spend the money saved on some LMR-400 coaxial cable or better.
Long answer: The CommScope weighs about 30 pounds more and that's without the mast to hold everything. The Diamond is omni directional and the CommScope could be, if you set the elements in a omni pattern like north, south, east and west. The CommScope is often used with a repeater system and all elements pointed in one direction for maximum gain, or slightly askew (Two aimed south and two aimed SSE) to make a wedge coverage shape, as an example. There are other things you need to consider when installing that type of antenna as well. Others will probably chime in on that aspect.
I also should point out that you may not need a $300+ antenna. You need to consider how you will use it. If you plan on using it to talk on local repeaters, a sub $100 antenna may work fine. If you plan on using it for simplex coverage as well, then the Diamond may be beneficial. Alternatively, for maximum focused TX and RX, a vertically polarized Yagi would be best which requires a rotor and more. Still, you need to consider the weather environment of your location.
Consider this: If you have a mobile setup now in your vehicle and you can hit the repeaters and talk simplex to who you want, then a sub $100 antenna on a mast at your home will typically work much better than your mobile setup. This is due to the additional gain the antenna offers, as well as its height above average terrain.
That Tram 1480 k9wkj mentioned is not a bad antenna. I have one and it works well. I used 3M 88 tape and then coax tape on the joint after putting it together. No problem with water. For $50, and you may find that for $50 shipped, it is an inexpensive test antenna that may be a fine solution for you. Of course where I live most repeaters are around 3600' - 5500' ASL, so it is easy to TX and RX into them. One must experiment.