Need some help on amplifiers...

[Zaphod]

First of all thank you in advance for any input you may have on the following questions, and I apologize for my ignorance.

My question is three-fold. The first is based on my current setup my fronts and my center are bi-wireable/ampable. If I run a seperate amps for my fronts and my center to bi-amp them is this going to throw off the total sound space, where the front three speakers will be receiving more power than the rest of my surrounds since the receiver I use is putting out 90 W per channel and the seperate amps would be 125 W per channel for the front L/R and 200 W for the center channel.

Next assuming this would be ok, for the L/R to bi-amp would you need a bi-ampable amp, or could I use a 4 channel amp and use two channels for each speaker, or would I have to buy two 2-channel amps to do this. Also the same question would apply to the center channel.

Now assuming this is ALL a good idea and will greatly improve the sound of my system and movie watching experience, what types of amps are good...without breaking the bank.

Now for the setup...here is my current system:
Onkyo TX-SR605
Sony 60 GB PS3
Fronts: Klipsch RF-25's
Center: Klipsch RC-64
Surrounds: Klipsch RS-35's
Sub: Klipsch RW-10

Also from what I have read, it is better to bi-amp. Am I safe in my assumption or is bi-wiring not that much of a difference as far as sound quality goes? Thank you again for any input.