The TR-4CW would be my first choice. As you said, the TR4 doesnt have the 500 hz CW filter or RIT.
I took this one home due to the excellent condition and lack of mods by anyone. Prices have skyrocketed and this was decent for the age and condx.
I really did enjoy the tube audio on CW in the few hours it worked, I could see using a sharp audio filter in the future.
I hope to be back on the air by next week!