You don't need a 4,400 gph pump just for the UV filter -- that is just the maximum flow the UV filter can handle. (In my set-up, I am running about 1,300 gallons per hour through the UV-2 filter even though it is rated to handle almost double that).
However, for a pond your size, I think you are going to end up with a pump in that range anyway. In addition to the UV that you choose, you need to consider whether you will be lifting water to a waterfall; the pipe length from pump to discharge point; and pipe dimension (bigger is better). If you want to get into the details of this, there are other discussions on this board on calculating "head height" - that is, estimating the affect of gravity and friction on the output of your pump.
For your pond, you will want to turn over from 1350 to 2700 gallons every hour. So you need a pump that will deliver that amount after calculating pipe length, height of waterfall, etc. As an example, this Pondmaster HyDrive 4000 will deliver 2,350 gph at 7 feet head-height; and 2700 gph at 5 feet head height. (The 3200 gph model would also work for your purposes.)
http://www.azponds.com/flowchart/PM_PRO_flowchart.jpg
Other good options might be a TetraPond DHP 3600 or DHP 4200; or the Laguna Max-Flo 4200. I found all of these models on AZPonds. Importantly, for a pond your size, I would not go with less than 1.5" pipe. All of these pumps mentioned have the option of 1.5" output.
