the Tein H tech springs will be a minimal drop (less than an inch IIRC) but the avenger weighs more, so they might drop more than an eclipse/talon. don't know if they will require camber kits with that little of a drop.

for just a comfortable ride the KYB GR2 struts are similar to brand new stock struts. easy on the backside and they deal with small suspension drops well
you can usually find a set on ebay for ~$150

don't do the AGX struts with any lowering, the strut body is too tall and can bottom out even with factory ride height on nasty roads.

eibach prokit is about ~1.5" drop IIRC, and will need camber kits to keep from destroying tires