There are a few places that still have $5 blackjack tables. Sahara, Slots-a-Fun, O'Sheas and Bill's Gambing Hall (the ex-Barbary Coast) all had $5 at some time while I was there last month. Sahara advertises that it still has them constantly (which they might) but it may be only one table during peak hours. I don't recall the Harrah's joints having any $5 tables, and I know the MGM-Mirage group definitely don't have $5 tables any more.
As for 6-5 versus 3-2, if you're playing a shoe (6 or 8 deck) it'll probably be 3-2. Nearly all the 6-5 tables were single deck blackjack. It's rare to find double-deck blackjack (only places I found was the Venetian and Harrah's) and interestingly they were 3-2 as well.
At least, that's from my last trip.