True bookshelf speaker

If I were you, I would consider a sealed (acoustic suspension) speaker for a bookshelf.

Rear ports won't sound right without 'space' behind them; and front ports have their own issues.

Have a look at www.nsmaudio.com

WEEZ

NHT makes a series of speakers with adjustable dispersion, allowing optimized response for bookshelf mounting at the flip of a switch. A year or two ago, I seem to recall that Stereophile liked one of these models very much.

If memory serves, Linn made a model called the "Kan" which was designed for use up against a wall.

Studio monitors like Lipinski's are also usually designed for difficult environments and might also work well.

God Luck.

Marty