Another vote for H&V! We really enjoyed our meal there. There's so much on the buffet everyone should be able to find something they like. I know all four of us did, and we can all be pretty picky at times.
As far as what time to make a PS, we made ours for 6:30 in June and that was perfect. Plenty of time to eat and get to Fantasmic. You can make your PS 90 days out from the date.
Also be aware that when you make the PS you may only be given the option to dine at 4 or 4:30 - nothing later. That happens a lot. What I (and a lot of other people) do is just go ahead and make a PS for that time, then call back later because they open up later dining times for the package usually within a month of your trip. I know in our case, later times opened up about 3 weeks out.