Oh I feel you! I have 3 of my own as well (5.5, 4.5 and 18 months) though thankfully the older 2 are in school. I am dreading this summer...
I also have 4 dck's currently: 5.5 yr-old in school then 3 full-time: 2 almost 4-yr-olds and a 2-yr-old, along with my own 18-month-old of course. The 2 that are almost 4 are both fairly new, and both gave up naps long before they came to me. We have slowly been getting better at quiet time, but I am definitely looking for kids under 2 when September comes, as one of the 4-yr-olds is leaving and the other is starting jk and so will only be here b/a school.

I know a lot of providers like having a range of ages, and I do to some extent, but given the choice I would much prefer a house full of babies. They may be difficult, and things may take longer to accomplish, but I am soooo done with the no-napping and the talking back and the fighting and the getting-"bored"-every-5-seconds. Give me a bunch of babies that are happy chilling on the floor playing and then nap for 2 hours a day. No more three-year-olds! Lol

Good luck with the quiet time, it's easy to say but much harder to enforce! Frankly, if it helps, go with a movie. Like Secondtimearound, that's the only time TV is on in my house too, so it helps a bit...for like 20 minutes!