If you are 20 years from retirement, I would not be investing in bond funds. They are for the conservative, risk averse, and for those who are close to retirement.

You should be 100% into equities. Your other choices look reasonable, but I would check each of them out on Morningstar.com to see 1) how they perform compared to their respective index, and 2) what their expense ratio, 12B-1 fees, and other expenses look like.

An expensive fund that consistently out performs the indexes may be worth its cost, but do not settle for an expensive fund that underperforms.

Your diversification looks fine for your age. I would consider Vanguard Institutional Index Fund as a core investment--suitable for up to 100% of your funds. The others may be OK assuming they perform as described above.