I own all three of the watches mentioned. I would describe them as follows:
1. Apollo 11 50th -
Elegant homage
2. DSOTM Apollo 8 -
Tech flashy
3. Classic Speedmaster -
Tool
You have ruled out the Apollo 11, but I personally think it is the most compelling of the three. The Apollo 8 is in the larger ceramic case with very innovative dial and movement treatment, you either like it or not. It's a very comfortable watch on your wrist and looks the part. It's also about 50% more expensive than a sapphire sandwich.
The standard moonwatch (hesalite or sapphire) is the quintessential tool watch. Recognizable from afar, it serves its purpose. It's a classic.
If you are only going to have one Speedmaster than I'd go for the classic edition, if it is part of series of Speedmasters in your collection I'd go for Apollo 8.
If you want the leather strap classic version, and are buying from an AD, I would buy the bracelet version which is just a $100 more, and then ask the dealer to include a leather strap and Omega deployant buckle as part of the deal. Most dealers will do this and it gives you more flexibility and will make the watch easier to sell down the road. Even if you figure you'll never sell it you never know, times and tastes change.