Help me prepare kitchen plumbing
Your valves appear to be a compression connection not   threaded  on to a threaded adapter. No need to un-sweat, you have plenty of pipe to work with, just cut below the tee.
Once your cabinet is put in over your stubs You will be able to build it any way you like. A water hammer leg at the top of each line is a good idea. You can choose any type valves you want, compression, threaded or soldered.
I prefer to have one valve for each supply line, as opposed to two lines off of one valve, so if the dishwasher goes on the blink you do not have to turn off water to the sink while waiting for it to be repaired. (same for fridge etc.)