best home base in sicily

Sicily is a large island. There's no such thing as a home base from which you can see most of the island. However, 8 days wouldn't be enough to cover the entire island, anyway, so I'd suggest thinking of this as a trip to a limited part of Sicily.

To me, the areas with the greatest concentration of sights are Palermo (with easy access to Monreale and Cefalu) and Siracusa (with reasonable access to the Baroque towns of Noto, Modica, Ragusa and Scicli). If you really must limit yourself to just one base, I'd pick one of those. You won't be able to visit the other one. Neither of those bases will give you good access to the following:

Taormina/Catania/Acireale
Trapani/Erice and the northwest corner of the island
The center of the island (Piazza Armerina, Caltagirone, Enna, etc.)
And the major Greek ruins at:
Agrigento
Segesta
Selinunte

Sicily has rather limited rail service, and none of it is fast. There are some buses as well, but they are usually frequent [<< meant to day "infrequent" here], and it seems that virtually no buses head to out-of-town destinations on Sundays. Those factors are part of the reason why a single base isn't a good approach to visiting Sicily.

It's possible you can manage to reach one or more of the places I listed above if you're willing to spend a lot of hours on public transportation, but the long round trips would waste a lot of time. If you're willing to rent a car for part of the trip (don't drive in Palermo!!), you can take a look at the estimated driving times on ViaMichelin.com to see what might be practical. It looks as if a car (perhaps rented at the Palermo airport) could make a day trip to Segesta possible. Or there's probably at least one company offering bus tours to Segesta from Palermo.

If I had just 8 days for Sicily, I'd split the time between Palermo and the Ortygia (medieval) neighborhood in Siracusa.

If the timing is right (if you're not landing in Sicily after a transatlantic flight) and you fly into the Catania airport, you might be able to head straight from the airport up to Taormina or Catania and spend part of the day there before heading back south to your first hotel in Siracusa/Ortygia. There's both rail and bus service along that route.

Sicily has so much to see that 8 days is not enough and will go by fast. But in 8 days you can get a great introduction to Sicily. I think one single location for all of your 8 or 9 days is very difficult to work with but it depends on what you want to see and do. I suggest that you choose either the eastern side or the western side of the island if you want to stay in only one home base, and then concentrate on that general chosen area. Otherwise, I would spend dedicate four days to each side and use two bases, or maybe 3, 3, 2 configuration if you want to see Piazza Armerina and Agrigento. What are your priorities and must see sites? For example, if you base in Siracusa, then it's way too far to go back and forth to Palermo or Cefalu or Segesta or Erice as daytrips, even with a car. Same is true is you base in Palermo, then a daytrip to Siracusa/Ortygia, Noto or Ragusa is just too far. Even if you just concentrate on one side of the island there will be lots to see and do. Will you be driving? Will you use busses and trains? Do you want to stay in big cities or are you looking more for a small town or coastal experience?

Eight days is like simultaneously a lot and not nearly enough. It’s a lot for one city, but not nearly enough for you to see much of the island. Either choose Palermo or Sircacusa areas. You can do a few nights in a smaller town nearby (for Palermo I’d pick Cefalu.) Both areas were great. We don’t have anything else to go on here, so pick whatever sounds best.

thank you both for your guidance; we'll need to make some decisions

If you have a car and are willing to move around you can see a lot of Sicily in 8 days. This what we did in 10 days and if we had a redo would leave off Cefalu. You could also leave off the Etna drive, though we loved it.

1. Arrive Catania drive to Taormina via Castelmola
2. Etna wineries loop, back to Taormina
3. To Ortigia
4. To Ragusa via Noto
5. Ragusa - Modica - Scicli - Ragusa
6. To Agrigento via Villa del Casale
7. Agrigento
8. To Cefalu’
9. To Palermo via Monreale
10. Palermo
11. Depart from Palermo for Rome

Happy planning!

We've decided to go to the eastern part of the Island and would like to rent a 4-5 bedroom villa outside of Catania, preferably in a small town. Any suggestions?