Not unless there was something that could have been sucked into the engine when the 2nd gasket was missing. You should be okay.
If you're into dumpster diving, try to find another Impreza with a similar intake/filter setup at a junk yard. Grab the filter out from that thing and then hack it up like I described above. Another thing you can try is to find the intake plumbing off of a MY98 - I believe they're differen than the MY99's. It's got a box, but no filter up there. Should be able ot get things to match up.
Hope that helps!