In my opinion the banshee front shocks would be worse than stock for serious racing. Do you feel it's more important to have a smooth ride, or minimal body roll and bottom-out resistance? The banshee front shocks really aren't any better, they're just the same shocks but softer and with progressive rate springs. Even if you made the yfz shocks fit, have you ever rode a yfz? Trust me, even though they're adjustable they're still the wrong way to go if the raptor shocks are too stiff for you. To me even the raptor shocks are really soft, and the yfz shocks are on the harsh side.
I run my raptor 700 in conditions ranging from trail riding to motorcross, flat track, and high speed xc-style riding. The only time I prefer a softer setup is trail riding and rough technical stuff.
I think that you will find the banshee rear shock will be a good improvement for what you're looking for though. It has about the same bottom out resistance as stock, but more adjustability and it doesn't make the back of the quad buck like a wild bronc over the rough stuff.
I think a set of aftermarket shocks for the front is the only way to go for you. A decent quality and properly set up aftermarket shock will have a good balance of plushness in the high speed damping over uneven terrain, but sufficient damping to control body roll in the corners and prevent bottoming on big jumps. I had works shocks and honestly, i thought they were crap, i'd stay away from those. I hated the way they were set up, and even though I told them to set them up on the stiff side, they still seemed ridiculously soft for me. The quad rolled way too much in the corners, it made it feel like a 600 lb utility quad, and i'd have problems eating up suspension travel too quickly and tearing up my skid plates on rocks because of it. It took about a year before the pieces of trash started leaking oil at the seals. That's piss-poor in my opinion. I have a rear shock on my old dirt bike that's 19 years old and still isn't showing signs of leaking.
That being said, I think Elka shocks are overrated too, but still better designed internally than works and they seem to have better satisfaction rates with their customers. My choice for aftermarket shocks was always TCS, which recently was bought out by Race Tech, also a good company. They're a little more expensive sometimes, but to me, well worth the extra cost. TCS quoted me around $800 for fully custom front shocks with compression, rebound, and preload adjustment, and remote reservoirs. I suggest you contact Race Tech and get a quote before you make any decisions. A non reservoir set might come in pretty close to your $500 budget, assuming the prices didn't change drastically when they got bought out by Race Tech.
You could also contact ATV Suspension Tech, they deal with most of the big name suspension companies and helped me out a lot with advice when I was deciding what to do with my suspension after my bad experience with the works shocks.
