If by optical sound you mean a lightpipe connection then the simple answer is no. In transporting a digital stream the most important factors are that the ones and zero's are never confused and that they happen at the correct time. Getting the ones to to remain ones and zeros zeros is the easy part. Timing distortions (jitter) increase as the length of the connection increases. For runs of more than say 5 meters the HDMI and lightpipe protocols become tricky whilst co-axial sp-diff can go 100m with ease.
Inherently the optical receivers turn on faster than they turn off causing a slight distortion of the on and off times. The bandwidth that can be achieved on lightpipe reliably is lower than on an electrical connection e.g. the MADI protocol (which is not really a home format but I mention it to illustrate the bandwidth issue).
That said the typical home theater environment is well served by HDMI or lightpipe or electrical co-ax (sp-diff) connections between sources and the amplifier and all modern equipment in your price range includes good re-clocking hardware to correct for jitter. Any of these protocols do fine over short runs - the bottlenecks in quality then remain the digital to analogue converters or the power amps themselves.
A bigger decision about your signal route comes about because flat panel monitors and DLP projectors have a delay in displaying the picture. If your TV/Projector has audio outputs these are likely to be corrected to be in sync with your picture. Some people thus recommend sending the different sources to the display and then always listen to the audio out of the display. If this is what you wish to do then:
1) You need a display that has an audio output that is time corrected.
2) You need an amp that allows you to send (typically HDMI) from various sources to your display, yet always listen to the audio output of your display.
If you select this signal path then please be aware that if you see any picture artifacts on account of extended cable runs then the audio is also compromised.
I personally prefer to keep the audio signal route simpler and fall into the camp of people who would rather send the picture to the display from the amp and feed the speakers from the amp without round tripping it through the display. Mostly I prefer this approach because it allows for a wider selection of displays. Many good projectors in particular still do not have time compensated outputs.
Another reason why I prefer this is that HDMI cabling is often pushed to or beyond the limits of accurate data transmission where a projector is involved.
If you go this route you need an amplifier that
1) Allows you to to specify a delay that matches your picture delay.
You would also need to either be confident in your subjective assessment of sync or look at a tool such as the syncheck
http://www.pharoahaudio.com/syncheckproducthomepage.html
Despite my soapbox about audio sync many people are very happy with the experience of watching slightly poor sync. It is your call whether it bothers you or not. In the price category you are looking at I think it is an area where people often compromise without knowing that they are compromising.
Yamaha seem predominant locally and do have good product. I am not personally that crazy about the way the user interface conflates many choices yet many people like this - and I understand the motivation behind their "scene" based approach. Rotel, Marantz, Denon and NAD have always been worthy amp manufacturers and ONKYO are I feel often under-rated but I disagree with Overkill69 that other manufacturers are not even worth considering.
As always google home theater forums for direct user experience.
Overkill69 raises a point that I never even personally consider - the DSP spatial algorithms. I am of the philosophy that I wish to hear the spacial aspects of a recording accurately. Every algorithm I have ever heard has at best been initially wow but discarded after the novelty disappeared and the accuracy of the original is what I return to time and again.