In my personal opinion pretty much any sub 2500 coilover system is not going to be designed for real DD, yes people swear by BC, Megan, D2, Ksport, Tein etc they are not designed the same way Koni, Ohlins, Prova, STI and other higher end companies do. 99% of the time they will throw a 8k/6k springs and make shocks hard enough for fillings to come loose in your teeth as you drive over anything thats not perfect flat road surface. The only reason to run them is for clearance, and height adjustment. Because they will be harsh prepare to replace every rubber parts associated with suspension on your car as they will, if not already, fail.
In my opinion if you really want coilovers get a very good brand used set that can be rebuilt by someone local. Sometimes local shops can make wonders to otherwise thrashed coilover system from re-valving to simply swapping proper springs.

Now since you do want to swap hubs and my guess is you don't have the money now, buy a set of used struts to roll for time being a working set can be bought on one of many subaru forums for 50-200 bucks for all four corners assembled with springs and all the hardware you need.
Once you swap the hubs decide what you want to do.
I never had Koni's but from other people and their reputation they will most likely handle better than cheap coilovers.