"Giving my experience in TKD (the most compared with other MA) I rather prefer if need it to fight in long range using the feet to the lower part of the body. I don't feel confortable and even frigthen in CQB cause my grapling and throwing techs are poor."
What do you consider long range? In my opinion, if you're close enough to kick someone in the leg or knee effectively without entering movement, you're actually in medium to short range already. After all, leg kicks are made at an angle, so your full leg length cannot come into play - this makes a difference in the distance from your opponent where the technique is a useful one.
"What would be your confort zone?"
It shouldn't matter. People from striking systems like TKD need to be able to hit hard with precision from the short, medium, and long ranges. You don't have to be a grappling expert who loves to roll around on the floor, but you do need to be able to use your knees and elbows and other short strikes AND BLOCKS effectively.
"Don't know right now but think I can benefit from taking some judo lessons cause I want to learn how to take an oponent down and perhaps finishing him there."
Not a bad idea, but if you're not comfortable fighting from a close range with the existing techniques you learned already from TKD, I would suggest that might be a good place to look at first before taking on judo.
"In some place I herd that almost all fights end in the floor."
This came from a study made of police arrests, I believe. Naturally, the police need to take a suspect to the ground in order to restrain and handcuff him. I suspect the # of person-to-person fights end with a much lower percentage of going to the ground.