If you read the 4e DMG 1 the Parcel system in D&D 4 is a recommendation. I.E. "If you want to fight X Monster of Y Difficulty then you will need Z gear." The modules Wizard wrote were designed with the recommended progression of monster power, character power, and attendant treasure. Somehow it this got transformed from a recommendation to "This is how it done." To change the feel of the treasure system then you need to change this assumption.
If you want break away from the predictable 4e treasure system then I recommend your or your referee play the setting more realistically. Note this is not the same as realism in mechanics. The mechanics of 4e can stay the same. By realism in the setting you have a more natural distribution of treasure and monsters. Which is roughly like a pyramid.
The implication of this is that once you move beyond low heroic you will be fighting a low of creatures on the low end of the scale while traveling through wilderness or town. The treasure will likewise be low end stuff. To find the better treasure you have to seek adventure and go to places that are more challenging. You find those places by roleplaying and tracking down rumors and legends.
I realize that this doesn't sound too much different. However unless you go seek those place, put yourself in harm's way,you will never gain better treasure. You may continue to level because you overcome various roleplaying challenges. This system divorces the gaining of treasure from the gaining of level.
Doing this will go a long way to restoring the mystery of finding treasure.
Gold buys people
Without a readily available source of high-end useful items, you can purchase large quantities of low-end things.
For example, a hundred swords, a hundred kits of armor, a thousand man-years in soldier's wages and a dozen wagons of supplies can achieve a variety of things that a squad of powerful murderhobos can't.
A supply of gold can give (with some time and organization) a widespread network of informants that can be better than any 'gather rumours' check you can make. See Sherlock Holmes or Game of Thrones Varys for nice examples in fiction.
A band of henchmen can ensure that every night camp has multiple watchmen and a quick defensive encampment around it, as historical army detachments made at every nightfall - a dozen workers with shovels, axes and a supply of nearby trees can achieve quite a lot in a couple hours.
Gold buys services
If your desired magical device of power can't be bought, then it can likely be made. Not everything that's needed for it needs to be obtained by yourself. If it needs a McGuffin from the eastern mountains, a FooBar from southern seas and a thingamajig from the western desert, then you can go yourself for one of them, send a hired expedition (or two) of N-5 level adventurers for another, and offer a large reward (hand of princess optional) to whoever produces the third item.
What I mean, if you do have excess gold, then it is one of the instruments that you shouldn't hesitate to spend for plot goals instead of 'crunch' goals of character power.
Best Answer
The Rules Compendium has what you're looking for.
The Rules Compendium, p 295, has random loot tables in lieu of treasure parcels. This answer discusses the fundamental mechanics, It also looks like someone has made an excel spreadsheet to do the rolling for you.