Want to visit Siesta Key with my husband and two kids for one night in July. Basically just want a nice time on the beach and nice dinner. Beach front preferred if affordable. Finding many condos with one-week minimums. Any suggestions for a one-night stay?

Take a look at www.tripadvisor.com. #1 on their list is Sara Sea Inn. I checked their website - it looks great and doesn't say anything about a minimum.
www.sarasea.com

There is a Best Western Motel right in the heart of Siesta Village and across the street from a very nice beach.

We stay in Sarasota at the Marriot Spring Hill Suites. It's great with kids because of the 2 tvs, pull out couch, kitchenette and includes breakfast! It has a nice pool and the rates are pretty good. It's down the road from the airport and about 20-30 minutes drive to Siesta Key. There aren't many hotels at Siesta Key, mostly those weekly rental condos and homes you are talking about! Great sand there but also try Longboat Key and the great shopping and eating at Armound Square! Enjoy!

I have stayed several times in the apartments owned by Paige Hartmann at www.siestakeysuites.com. All of her properties are near the beach and have swimming pools. They are very affordable, clean and modern. Enjoy Siesta Key--it's WONDERFUL and the beach is fantastic. Try to stay at the north rather than south end of the island--the beach is much nicer.