Up to 60 watts is supported, but I would recommend a 4K screen with 3840x2160 pixels instead, it is less wide than a 34 inch monitor and offers a much better resolution also in height. The more pixels also bring a much higher sharpness for small letters.

This model would be very good, it can charge up to 92 watts, it also has Thunderbolt 3 and is ideal for a MacBook.

Samsung LF32TU870VRXEN (3840 x 2160 Pixels, 32")