the stock RydeFX are good shocks, I'd get them rebuilt / revalved. Should cost less than $100 for both. Where are you located, maybe someone has a local shock guy to recommend?
Also , how many miles on the sled, how much do you weigh, and what kind of riding do you do?
Adjustable shocks will cost a lot more - is it a "need to have" or just "nice to have" ?
For my high mileage 02 XC800, I bought a used set of RydeFX shocks and had them rebuilt before shipped to me, a very noticeable improvement in ride/handling. I also got a pair of new 90/180 springs to try out, but havent put them on yet. (Stock is 68/160)
Some of the best front shocks available for the edge is the RydeFX Solo shocks used on the 05 XC600 50th anniversary, but those are very hard to find used.