I strongly recommend you go OE-I just made a call on your behalf; they retail for $97 each, so can be had for about $ 80 apiece (be advised there are 2 different part numbers, based on your VIN-for the absolutely correct price email me your VIN). If you end up with a stiffer front end, your car would "pogo" and bounce at different rates & ranges front to rear-not very desirable.
If you install new front struts, be advised that they will be considerably stiffer than your current ones. Further, near as I can tell the front struts on my wagon work comparably to Bilstein HDs, but they don't quite deliver as "busy" a ride as that of my 300D (in which I installed HDs all front & rear).
I'd also consider rear Nitrogen cells, which run approximately $100 per side. If you go this route, you can't go wrong and if the ride's still loose, then the only thing left to spring for are the rear hydro-struts and you're done.
"If everything seems under control, you're simply not going fast enough" --Mario Andretti
1995 E500 street car
1986 Porsche 944 Turbo S track car