It's a decent sized room w/ 12' ceilings so definately don't want a smaller speaker, but the speaker is sitting on a large bookshelf so I only have 17" in height to work with. I was looking at the sierra's but since they are rear ported I am concerned i don't have enough clearance from the wall.

thnks

Budget? Are you looking for fronts only or a complete setup? How big is your room? How loud do you listen? What will you be using to power them?

$2000 max for the 2 fronts, room is open on sides as rear so all in the space is over 1000sq feet, obviously not ideal setup for a small speaker but trying to do the best I can

B&W 705 or 805. Beautiful sounding speakers. Go give them a listen.

Room filling on a budget i would look at Klipsch reference line.

anything else?

NHT Classic Three is sealed, all kinds of good reviews if you Google it, though you'd want opinions on whether it makes sense to use it in your intended location. There's more to it than porting, as you know I'm sure.

http://nhthifi.com/current/products/speakers/three.html
http://www.google.com/search?q=nht+classic+three+review

The NHT M5 and M6, OTOH, are designed for that kind of location (boundary switch) and can be used horizontally IIRC. You might still be able to find them on clearance.
http://www.nhthifi.com/2006/products/ht/m6.html

Some of the Monitor Audio stuff is front ported IIRC
http://www.monitoraudiousa.com/product.php?range=8&product=56

Dynaudio 42W
http://www.dynaudiousa.com/products/audience/42wall/aud42w.htm

Some Focal stuff
http://www.focal.tm.fr/
http://stereophile.com/standloudspeakers/1107focus/

Thanks buzzy, very comprehensive, lots of good options in there. I have yet to find the perfect combination of something with sufficient SPL capability for my space as well as the range for Ht, but obviously there will be comromises when dealing with my limited placement options

Mackie HR824.

http://www.mackie.com/products/hrmk2/index.html

They have acoustic space controls to deal with placement near back and side walls. They also have solid bass response down to the mid 30Hz range. I'm not sure if they are under 17" tall though.

Paradigm Studio 20s or Paradigm Signature S2s. Both front-ported.

If you're concerned about range for HT, just about any bookshelf would benefit from the addition of a sub.