Firstly, I think any way you can best manage the inherent juggle of life and work with kids that makes sense to you is the way to go!
With napping...and most of my son's same-aged friends have followed this pattern....once it was one nap, down by 12ish, nap 2-3 hours. Time for fun in afternoon, bedtime more around 7pm. BUT as my son and his buddies approached 2.5, nap time was pushed to be more around 1pm (sometimes even later), and I kid you not, some days its *well* over 3 hours and he's still snoozing away. Bedtime is usually a tad later - 7:30-8pmish. Wakeup times are no different, its still way early (6-6:30am-ish!). It has been a bit harder to have him napping later in afternoon. If he's not up until after 4pm, it doesn't allow much time for activity before dinner. This was especially problematic in the winter when it was dark by 4:30 too! In general, he's a happier camper in the morning, so that's when we get the most accomplished (errands, toddler classes, playgroups, general fun). And its predictable. You never know exactly when the nap is going to begin/end, even in the most structured of settings, so I have found it much more difficult to plan anything for the afternoons and like to keep that very loose.
In terms of how an older toddler's patterns may affect your work scheduling, it may sort of be a "six-of-one-half-dozen-the-other" situation. Do you want to juggle your child care/work every day or just 3 days a week? A good friend of mine went from working PT every day to 2 full days recently and really likes this set-up. Her kids get a full day at the caregivers (breeds consistency for their days) while she focuses all of her attention for 2 full days at the office. When she's not working, she feels like she's very focused on just her kids, instead of abruptly changing roles throughout the day. That said, if you worked mornings, had his nap time "off" so you can use it to catch up on other household/personal matters, you could probably still make afternoons work with your son since you will be focused on just him...in general, I do believe you can make whatever work. Even a car ride or a trip to the grocery store can be quality time if you make it so!