pre-amps for home theatre....whats your preference?

For sound quality, Anthem and Arcam.

For features, and knowing they are serious about HT products, Anthem.

The reason I say this is that Arcam seems to get in and out of the HT market while Anthem has been dead serious about it forever and continuously improved their room correction software.

Having said this, I don’t know why you’d buy an Anthem processor instead of a receiver, except for the balanced outputs, since the receiver is usually a grand or more less expensive. This gives you the option of adding as few or as many external amplifiers as you want. 

Would help greatly to know which speakers you bought, if you’re using a subwoofer, and your budget.  Also, is 2-channel music important to you at all or is this strictly a multichannel system?

sure..i just bought this setup:

Klipsch Reference Premiere RP-8060FA towers
Klipsch Ref Premiere RP-504C W center channel 
Klipsch Ref Premiere RP-502S W surround
Klipsch Reference Premiere RP-600M rear surround
Klipsch Ref Premiere RP-500SA - rear atmos
Klipsch SPL-150 x 2 subs

It sounds by your "all Klipsch" shopping list that you are probably not looking at the top end of budget.

Eric proposed Anthem as a possible suggestion.  This is a great suggestion if you're budget limited.  However, there are better sounding processors.  One thing here.  If you are really locked into the concept of getting into height/ceiling speakers for Dolby Atmos and DTS:X, you are probably going to be locked into lower end processors such as Anthem AVM 60 or AVM 70.

If you can let go of the ceiling/height concept and are willing to live with 7.1 channels, then you can potentially jump into a better sounding processor.  There were two suggestions above.

Bryston SP3 uses their discrete Class A analog output stages.  This is a critical part of the sound quality.  I will say that Bryston SP3 had just about the strongest bass output I've ever tested on any processor.  The combination of their massive power supply with the high-bias Class A audio circuits provides this result.  However, the upper mids are just a tad too laid back for my tastes in home theater.  Music was very pleasant however.  The Bryston also has fully discrete Class A input stages for all analog inputs.  It actually has 8 separate discrete stages for the 7.1 input and also a fully-balanced 2-channel input stage (if you have XLR sources).  Internally, the balanced input is converted to single-ended for processing/volume.  This puts the SP3 at the top end preamp arena.  If you have analog sources, the SP3 will perform just as good as many other dedicated 2-channel preamps.

Krell Foundation 4K is the alternative if you want better resolution with faster attach and impact on the sound.  This is critical for HT movies and such.  The Foundation does not have discrete audio circuits, but it's probably about the best you are going to get at this level.

Both support 4K and the latest bluray standards, but neither of these support Atmos.  I like the fact that both SP4 and Foundation have all linear power supplies (including the power supplies for digital).  Most processors may have linear power supply for analog, but still have a switching power supply for digital sections.

But like I said, if you really want all those extra Atmos ceiling/height speakers, then Anthem is the way to go.  I am of the opinion that I would rather have a totally awsome and realistic 5.1 system than an average 13 channel system.  You'll have to buy amplifier channels for all those extra speakers as well.

Your speakers are very easy to drive so not much power needed.  Yamaha AVRs are very good for both music and movies, and they’re one of the most reliable brands on the market.  Go to Accessories4less.com and get the RX-A780, which is from Yamaha’s upscale Aventage line and is on deep discount at $499.  You won’t be disappointed.  Best of luck.