All my opinion, but it worked well for me:
1. You should get a new chain, dont put the old chain on your nice new sprockets, youll have to cut it to the correct size, they come in one long strand that you size yourself. Its pretty easy, just count the links on the stock chain, and match the number of links on the new chain. 520 is lighter (faster accel) than the 525 you have on there right now. unless your at the track, you probably are ok with another 525 chain. its up to you, i got a 520 because it was cool. i didnt notice it was lighter or anything.
2. Go -1/+2. One tooth less on the countershaft sproket (the front one), two up on the back sprocket. its a little aggressive. your rev's are gonna be higher as you cruise down the road, and your speedo will be slightly off, but youll accel. really nice. when you pin the throttle youll notice the bike takes off.
3. i wouldnt get aluminum sprockets, i tore the teeth off mine. look for steel ones. the steel is a little heavier, but its stronger, and you are less likely to tear teeth off. when (if) your doing a wheelie or hauling ass down the freeway, tearing a tooth off your sprocket is not cool.
maybe a package like this would work for you, i just chose random parts, stuff i used on my bike:
DID xring 520 chain:
stealth rear sproket (aluminum but with steel teeth, thats cool):
afam sprocket:
thats how i did it anyway. maybe you would have better luck with the vortex aluminum sprocket or some other setup, but i tore through it so fast i told myself i wouldnt get another aluminum one.
you may want to get a speedo healer ($90 +/-). it lets you adjust your speedo. so if your going 25mph, it indicates 25mph on your display. this is nice when you have a pig behind you and your not really sure how fast you are going. the new gears will throw off your speedo.
You also may want to get a chain tool ($100)to size your new chain. Sizing a chain is pretty easy. I did it with zero exp.:
I know it's a litle extra money for the tools, but its worth it. you can swap back to your stock set up, and try different sprocket/chain combo's without having to pay someone else. if its gonna be a one time switch, you may want to borrow a chain tool since $100 is kinda expensive for a one time use. there are cheaper tool kits out there, but with some tools, its nice to buy a decent kit. i got a cheap chain tool kit in the past, and ended up throwing it away.