Hi Dessa,
I have a 99 lx sedan 2.3 i4.
RSB
I bought eibach's 23mm because I was scared to make the leap to the progress 24mm as I read that the exhaust hanger would need to be bent to fit it and I was new to the modifying scene and was afraid of that. Although, I also read that the progress would fit without it. I just didn't want to risk it.
The eibach is great, night and day difference with handling, stability, and reduction of understeer. But, at some point, curiosity will take over and I'll need to see if there's a measurable difference between the two and I'll get the progress. (Unfortunately, I have yet to see anyone on here or anywhere else write a review of going from eibach to progress)
FSB
From what I've read, most people do not thicken the front bar as it will induce more understeer at the limit, even if it's just .5mm larger than stock. The front sway bar for my car is 26.5mm not sure if you have the same trim but you could look it up online and find your stock sizes. If anything, people recommend just replacing the end links, especially if your car has over 150k miles. And this just allows the sway bar to function properly again. For endlinks, definitely get Moog. I bought an oreily's off brand and it didn't hold my rsb in place- it squeaked when I took corners. I bought moog and it solved the problem completely. Lesson learned.
Alright, having said all this. I would say start with a rsb and new end links. And if I were you, I would go progress, just because a good amount of members have had good luck with it, some having to bend the hanger some not. Sounds worth it as I look back at my own decision. But, you will not go wrong with Eibach either, that's the beauty of it! Go with whichever you feel more comfortable with. Then, or at the same time, upgrade the front sway bar end links. That will give you a good idea how your car will handle with a realiable stock front sway setup and an increased, and of course realiable, rear. It's also important to note your spring/shock/coilover setup will influence your handling with these sways so be aware! Remember, suspension is a system of different parts working together and they're all related!
Hope this helps!
-Avery