I'm about to buy a pair of speakers to a Roland V-piano but the question is what pair of speakers are best for my budget at $1000?
I think the first thing you have to think about is your goal.
Who is listening, where are they relative to the piano and what size is the room? And lastly what kind of "sound" are you going for? You can't buy speakers without knowing all of the above. Without the above information the advice you will get will all be of the form "I have X, they work for me".
If this is the simplest case of you needing to hear what you play in a typical living room. Then you have to decide if you want monitor style near feild speakers or larger ones that "fill the room". Moniors are acturate almost to the point of being harsh and the sound will resemble what you hear in headphones. Physically larger speaers of the type designed for stereo music listening will sound more like a real piano.
It is good to understand how a real acoustic piano sounds in a room. A real acoustic piano sends the sound in all directions 360 degrees. More then 99% of the acoustic piano's sound goes some direction other than to the listener. (yes almost ALL of it) But the sound hits a wall, ceiling or floor and then comes back to you and this is what you and everyone else in the room hears.
Monitor speakers are more directional and you aim them directly at your ears. Bigger stereo speakers are typically set up to fill the room so that most of the sound you hear is reflected from the room. SO you have to choose which you want, a very acuate "digital" sound or a simulation of an acoustic piano that is "colored" by it's acoustic surroundings.
There are many "shades of gray" too. At one extreme are headphones. The sound goes straight to the ears. At the other end of the spectrum is the Yamaha Avent Grand N3. It's speakers are vertically mounted and don't face the listeners at all, the sound first goes into the case and then is re-radiated into the room like it would be in an acoustic instrument. With $1K to spend you can afford any point along this spectrum you like.
I have both kinds of speakers. I use the monitors for "post production" type tasks like editing and the larger 40" tall speakers for live play.
The neat thing is that the cost is about the same
If these are to be used for a public performance then you have many other considerations. Thinks like "will they fit in my car" come into play. But heck if you can fit a v-piano in it's road case you must already own a delivery van.