Salt is the only way to go, but be very careful of the species you blend together...
I had a puffer toxify the entire tank once, and a it resulted in the loss of several hundred dollars in fish and live rock!
Our next tank will be a minimum of 125 gallons, and again be a wide array of "creepy crawlies" and schooling reef fish.
If you go with salt, beware that a healthy hand caught fish can easily cost between $25 and as much as $200 or more ([i]I've actually seen them approaching $1000[/i])... Therefore, quarantine tanks are a must!
As mentioned in a previous post; the day lights, night lights, chillers, heaters, power filters, trickle filters, power heads & protien skimmers get rather costly to run... but also DO NOT forget to put all of this on a very powerful battery backup system, since a temperature change of +/- 2-3 degrees can throw everything off balance!
After years of trial and error, we finally had a stable aquarium that ONLY needed water to be added as it evaporated. I would do a water change no more often than 6-8 months, and generally just did them on an annual basis.
We also had a few fish that actually like to be petted and hand fed! [:)]