AT&T’s LTE network is still in its infancy, but for those of you lucky enough to live in one of the markets where the service is offered, you’ll soon have a chance to start operating a smartphone on the high-speed network; starting November 6, AT&T has announced it will begin sales of the LTE-capable Samsung Galaxy S II Skyrocket and HTC Vivid.

Considering AT&T LTE service is only available in half-a-dozen Midwest cities currently (though that number will jump to nine by the time these phones are released, including an East Coast debut in the Baltimore-Washington area), it’s especially surprising to see AT&T get things started with two LTE-supporting Androids. Based on earlier comments, we were starting to think that the company’s offering of LTE devices coming out through the rest of 2011 might be a little sparse.

Unlike the 1.2GHz 4.3-inch Galaxy S II AT&T already has, the Skyrocket features a 4.5-inch Super AMOLED Plus screen and an upgraded 1.5GHz dual-core processor. It’s main camera is eight megapixels, two-megapixels up-front, and there’s 16GB of flash storage on-board.

The HTC Vivid also goes with a 4.5-inch screen, but in qHD resolution. We’ve been waiting for this one for some time now, showing up a few times as the HTC Holiday or Raider. It’s got a dual-core 1.2GHz processor, eight-megapixel main camera, and 16GB of internal storage.

Compared to Verizon, with its $300 LTE smartphones, this pair seems positively cheap. The Samsung Galaxy S II Skyrocket will run you about $250 on-contract, while the HTC Vivid can be had for a mere $200. At those prices, we wouldn’t be surprised to see these two become popular even where LTE isn’t yet offered.