I would try a 300 main, stock pilot, needle in the middle. A 340 will be too much IMO. Do a plug chop after you try that jetting. My suggestion would be to buy jets ranging from a 290-340 and start with the 300 and change from there if needed.. To give you an idea, I have more mods on my motor than yours and I'm at a 320 main at 5,000 feet.
On the reeds, I personally run V-Force 3's with my set up.
Good Luck!