I'm looking at getting a pair of bookshelf speakers or monitors for my bedroom. My budget is around $400 for the speakers and an amp. Two possibilities I'm considering are:

Yamaha HS50M

AV123 XLS with something like a Super T-amp

Also, something like a 3-in 2-out input/output selector would be nice, but I have no idea where to start looking for one

I'm very fond of the Polk Audio RTi4's, and even with speaker stands they should fit within your budget if you find a set used. T-amps are always good for amplification.

Kef iQ3.

kef fanboi.

Do anyone have any experience with the various T-amps?

I'm also looking at the Emotiva BPA-1:

http://emotiva.com/bpa1.html

I'm very fond of the Polk Audio RTi4's, and even with speaker stands they should fit within your budget if you find a set used. T-amps are always good for amplification.

I'll look into those, they seem decent.

Kef iQ3.

Do you know of a reliable website/dealer in the US? The only legitimate-looking site I found them on sold them at $400/pr in black

Do anyone have any experience with the various T-amps?

I'm also looking at the Emotiva BPA-1:

http://emotiva.com/bpa1.html

I'll look into those, they seem decent.

Do you know of a reliable website/dealer in the US? The only legitimate-looking site I found them on sold them at $400/pr in black

MM, Vans... but my recommendation is to buy used off A'gon or ebay fwiw: I paid $125 for my Q1 (which is the old name of the iQ3)

I'll look into those, they seem decent.

They sound great, the cherry finish looks lovely, are reasonably easy to drive, and don't really require a sub. I've never heard the Kef's though and am not sure if anyone on here has experience with both.

I would also add the Radiient Europas and the NHT Classic series to your short list of speakers to research further and hear if possible.