I've been reading on some other forums and the general view is that if you have high end speakers, such as the Paradigm Sig S4's for instance, you need a high end pre/pro/amp or receiver to actually get good sound from them. I'm thinking about getting the Yamaha 663, am I going to be disapointed with this combo am I putting to much money into the speakers and not enough into the equipment?
No. It is a myth that you need high end electronics to enjoy high end speakers. The myth is the result of:
1) Some speakers are a difficult impedance or extremely inefficient, and therefore require better (generally, more expensive) amplification. Most of the difficult impedances are found in high end speakers. But many high end speakers are not a difficult impedance.
2) Salesmen make more money if you buy expensive things, and if they see you can afford expensive speakers, they tend to be shameless about trying to bleed you dry with other expensive equipment.
3) There is a lot of BS in the marketing and claims of audiophiles, and therefore "magic" wires and other things are said to be required. Basically, the best speakers that money can buy will have greater frequency response anomalies and higher distortion than any decently made "mid-fi" amplifier operated within its design limits.
I have used speakers that retail for more than $6000 with a receiver that retailed for about $600. It worked great. (I now am using a receiver that retails for about $1600 with the same speakers, but that is only because I wanted more features. The sound is the same.) It all depends upon the difficulty of driving the speakers whether you can get away with a regular receiver.
If you want the best sound for your money, you will spend with that kind of difference in cost between speakers and receiver. Spend the majority of your money on speakers for the best possible sound for your money.