Hi!! Do you think I can get good mixes with headphones?
"Good" mixes is a relative term. What is "good" to one may suck to another. What IS important is translation. How well your recording translates to other systems and rooms. If you aren't planning on playing back your mixes anyplace other than your own room or system..it doesn't matter. If it sounds "good" to you, either in headphones OR over monitors, then..hey, their good.
However, IF, your intention is to "release" your recordings to other people, who will play them on other systems in other rooms, then you need to learn to "trust" what ever you are listening through is telling you the truth. If not, then you have to learn how to compensate while mixing. The only way to do this is by playing back your material through other systems in other rooms, cars, etc. Once you hear the difference between monitoring through your system and someone else's, over time you will learn how to ..ahem..compensate. The fact is, EVERY room is different, and affects the sound in some respect. Even the "listeners" rooms. This is why control rooms are designed with as flattest room response as possible. This way, the engineer is reasonably sure the recording will translate in 90% of consumer rooms. Play a recording back in a Cathedral..and you will see why.
Believe me. THIS is the entire crux of mixing in a room and monitors that don't LIE to you If it lies to you while recording, then it lies to you again while mixing. Here's the deal.
For home recording enthusiasts, the dimensions of the room dictate those frequency wavelengths which are problematic. And the easiest solution is to use absorption in the corners of a room as this is where Low frequency sound waves terminate, and reflect. Hence all the talk here about "bass traps". Which..btw..they do not "trap". Absorption works by virtue of "gas flow", whereby the air molecules are forced to move through the "interstices" of the material, which turn the mechanical motion into heat by virtue of "resistance". This is why rigid fiberglass with 3lb density is the preferred material for absorption devices. Furthermore, the thickness defines the low end of absorption coeffiecients, as resistance absorption works on the 1/4 wavelength theory. That is, the thickness determines the lowest frequency of absorption by virtue of 1/4 of it's wavelength. In that regard, an airgap behind a given thickness of an absorber, will lower the frequency it will absorb. Of course, not all frequencies are absorbed the same. Absorption materials are rated as an absorption "coefficient" at various frequency "bands" by virtue of testing in acoustical laboratorys. However, virtually all materials will never be rated below 125hz, as it's almost impossible to determine absorption below 100hz. But it doesn't matter. What DOES matter, is to place as thick of material you can in the corners. All corners. And the smaller the room, the more the problems...ie.that's why I told you that in that little space, it wouldn't matter what monitors you use. They would ALL lie to you.
In essence what I am trying to tell you is this. It is more important to treat your space correctly than what brand of monitors you use, as "most" studio monitors are designed with as flat of frequency response as the manufacturer can get vs price point. So there you have it. Buy whatever monitors you can afford, but what ever you do, they are NOT going to perform truthfully until you treat the room.
Hope that helps. And yes..moving to a larger space will help in that endeavor, as I see no way that treatment will help with low frequencys in that small space. Given you could even fit some in there as it would have to be...well..as thick as the room is wide.
That's not to say some 2" thick material on the side walls "won't" help with mids/highs and early reflections. But I don't see it helping enough to trust your monitors in that small space.
Ok, agian...this is only my .02 cents. Good luck.
Holy moly. And here I thought I had a small space. However, to tell you the truth, your space is so narrow, and the sidewalls so close to the listening position, I don't think it's going to matter what monitors you buy. The side reflections are going to be a problem. And since they are so close, I can't see even wasting money/time on absorption panels. This is one of those cases where you live with what you have and simply do the best you can to record. However, you'll never get rid of comb filtering in that space. Sorry. 
