For under $800, you may want to check out Paradigm's Cinema speaker system. Here's a review: Paradigm Cinema Speaker Review
You can buy the complete 5.1 system for around $700 USD.
You may also want to consider putting your $800 toward a nice set of mains and add the rest of the speakers and sub later
BTW, finding the "best" system really depends on your ears. You should try to audition every recommendation that you receive here. Also, do a search and see if just how many recommendations are available on past threads. Enjoy your hunt
Two pair of JBL N26II bookshelves (could go with the N24II for surrounds to cut cost a little more) with a N-CenterII and an Adire Rava sub will come in at around $850-$900 mark.
Home Theater Direct Level 3 center, Level 3 bookshelves for mains and Level 2 bookshelves for surrounds with Rava will also come in at under $900.
The above don't take into account shipping, you'll need to add a little more for shipping.
If the Synergy system is the SC1 with two pair of SB1 monitors, then that along with a Rava would be a great little system. If it is the quintet or the SC.5 or SS.5 I wouldn't go for it.
I would check out Axiom speakers. They have great deals on their factory outlet speakers. Just putting in my 2 cents. Look at www.axiomaudio.com.
Daniel