There are a lot of posts on here about the best fluid to use. I suggest you go through them and see what you think. You can never go wrong with Honda MTF, as for any gains you will see from using anything else, I'll leave that to you to decide, a lot of smart Honda folks have posted their results here. I think more important than the fluid choice is actually just getting the old stuff out of there and making sure the level is where it should be.
If the noise goes away in higher gears, it sounds to me like input shaft bearing. A throw out bearing noise will always be there when the clutch is pushed in, regardless of what gear you are shifting into. The input shaft bearing in my CX howls like an M22 (sorry, old Chevy transmission reference there lol) in 1st gear, but 2nd is way quieter, and 3rd is silent. The good news is that they can go for a long time making noise before you need to worry about them. Though in your case, it may have already been making noise for a long time, one of the perils of 20 year old used cars. Start with a fluid change and go from there would be my advice.
