Water! - Cruddy tap water to deionized (any reverse osmosis experience?)

I currently have well water. The stuff is...interesting. Currently, it's pretty reasonable quality. Middle of winter though, I'll have some chlorides in it. Lots of iron, reasonable quantity of sulfur. Always clogging up the coffee maker, shower head, etc.

I'm considering putting in a reverse osmosis system to get one step closer to having deionized water. I may go to a full on deionized water system later, not entirely sure if it will be necessary.

The addition of my tap water to concentrated aqua regia has precipitated small amounts of gold.

I'd like to buy one of these "under the sink" RO systems for the lab. They claim up to 75 gallons of water a day. Does anyone have any experience putting one of these in, and feeding it with filthy water? Should I be installing a spun fiber filter and carbon cannister before it hits the RO system?

I should probably have the culligan man spec out a system, then just build it myself...but this is good information for the forum.

Sick of buying distilled water.

At my work they use two 90 GPM RO water units. In the past they fed them with soft water to avoid plugging the membrane. Years ago my parents had a small home unit with the same arrangement.
At work they now meter some sort of pretreatment additive into the feed water instead, but I don’t know if that is feasible on a small scale.
Dale