I'm not sure what e6 or e10 is.
e6 is a 3e/3.5e D&D variant that simply stops at 6th level. (Every N xp after that simply gives you another feat.)
For 4e, there's also a "inherent bonuses" approach that eliminates the need for magical items to make the math work.
I'm simply suggesting that tweaking things (rules/expectations) to avoid finding treasure and limiting leveling out may provide most of the feel you are looking for with much less work that converting everything cool to Shadowrun.
