Why would you not want to install anything yourself?? It's the best feeling ever hooking something new up and getting in and slamming to it!
And for 350 install included your options are kind of limited.. Craigslist would be a good start for that.
I currently have about 3K in mine.

__________________
1999 XLT 3.0 Stepside. Air box mod. 15% Tint. 31" Nexen Tires. 180 amp Alternator. Soundstream VIR-5000 Touchscreen Headunit. Addictive Audio ELITE 100.1D mono amp at 1 ohm. Jensen 600 watt 4 channel amp. 4 Pioneer TS-A 6x8's up front. 2 Pioneer T-SA 6x8's in back. 2 Pyramid Titanium Super Bullet Tweeters. 4 12" Kicker CVX's.