The Highline Trail is, as I recall (too lazy to look it up) 70-some miles long between Big Sandy Openings and Green River Lakes. If you take some side trips (mandatory, IMHO) such as to Cirque of the Towers, Golden Lakes, Titcomb Basin, it will be longer, at least 100. There is a shuttle service through the Great Outdoors Shop in Pinedale. There are a zillion lakes and it's a fisherman's paradise!
IMHO, the best current book on the Winds is Nancy Pallister's "Beyond Trails in the Wind River Mountains." Many of the best parts of the Winds are off-trail. While some require climbing gear and considerable skills, many are relatively easy if you have experience in off-trail route finding. Nancy's book combines on and off-trail trips and, of course, you can combine several if that is your desire.
IMHO, the Winds have the most spectacular mountain scenery anywhere (and I've been a lot of places!).
Edited later: If you're looking for "big country and tons of scenery," the Winds are THE place!
Coming from low altitude (especially Seattle), you should start at Green River Lakes (north end) which gives you a chance to acclimatize--you'll start at 8,000 feet and don't gain much elevation the first day, vs. starting at 9,300 and going up to 10,500 the first day from Big Sandy.
You'll want the large scale maps from either Earthwalk Press (which I detest) or Beartooth Mountain Press (with which I'm not familiar) for planning, and 7.5 minute topo maps for any sections where you plan to go off-trail. If you get the optional CD with Nancy Pallister's book (well worth it; the photos will have you drooling), you can print the relevant maps from it.
There are a number of trip reports on this site including the one mentioned in the next post here.