If I remember correctly. The headset supplied by LTK is a low-cost generic headset used by a number of low-priced Chinese frames, as it offers a couple of different C-Ring fitment options.
Given that this frame has an 8.7mm bore depth, you can fit your choice of FSA, Deda, Cane Creek, etc., upper bearings, as long as you use the correct 52mm (or 51.8mm) x 40mm x 8m 36/45-degree lower bearing; you should use those. It will minimize the need to replace the headset bearings in the future, and the track record for these generic headsets is really bad in terms of fit and preload retention. I personally recommend the FSA No55R LS, but I am happy to assist if I can. Some parts come with C Rings and covers, and it can be more cost-effective if you ask around first.
For example, if you are buying Deda Superbox V2 stem, it comes with a C Ring and headset cover, so all you need are the correct bearings: 52mm (or 51.8mm) x 40mm x 8m 45/45-degree upper bearing and a 52mm (or 51.8mm) x 40mm x 8m 36/45-degree lower bearing.