I think people get too carried away trying to get fancy schmancy chips to impress all their friends. The only reason I got 2 different kinds was so I can have 2 different games going at once (a $25 buy-in and a $50 buy in, a tourney finishing while a ring game starts up etc).
I think the 9 gram diamond chips are the way to go. They are perfect. Once the cards are in the air, nobody cares if the chips are fancy.
I'm real happy with my 2 sets of 1,000 chips each. I can always mix them if I need to, but I have the flexibility to run 2 different games. If you are going to buy chips, I highly reccomend the mix that includes a fourth color. I think our games are much smoother at cash out time since we started introducing re-buys that have the 500 chip in them. We have plenty of change (red and green) on the table with the first buy-ins.
My sets are both:
300 reds
300 greens
200 blacks
200 whites
If I had it to over, I'd swap 100 reds, for 100 blacks.
If you want to go with all 9 gram diamond chips, you could always get an alternate color scheme with the second set (orange, blue, purple, gray or something like that) so you still have the flexibility to run 2 differnt games at once.
Come to think of it, it seems to me that I just picked up 300 9g chips this weekend. If you'd like them to "complete" your 700 chip set, I'll be glad to transfer them to you for what I gave Doc. They're red white and blue, don't remember the counts on each.