welcome!
i live in mandeville (20 miles west) and it's a better place than slidell to live in my opinion; living on the water would be limited to river frontage, but most of these flow into the lake...the ones around bayou castine & bayou lacombe are very, very nice. you should have NOOO problem with that budget!
to get offshore (venice) it's 2.5 hrs door to marina from my house trailering a boat. from slidell, you'd get there 30 minutes sooner. THT member ringleader lives on a lakefront development in slidell, he'd have more info about that area
welcome again...