Here is some good tidbit of info for your car:
http://www.crutchfield.com/S-B1RxvdvmP5H/learn/2007-2013-suzuki-sx4.html
Here is the wiring color codes you will need: http://www.modifiedlife.com/2011-suzuki-sx4-car-stereo-wiring-instructions/
Will need to know a lot more about your budget and needs before could make any suggestions:
Do you want to be able to use steering wheel controls?
iPhone or Android?
You said you need Bluetooth, do you need XM, USB, 3.5mm AUX or other input sources?
Do you want rear usb so you can hide cable to glovebox or center console?
Do you want all-in-one woofers and tweaters for your speakers, or separate (separate system is better quality but costs marginally more)?
Do you want small, medium, or large amount of bass (this determines size and qty of subs)?
For your tastes would you rather sacrifice some bass for quality/clarity, or sacrifice a little bit of quality/clarity for more bass?
Here is a short list of what all this will entail, if this sounds overwhelming you may want to re-evaluate installing yourself
Stereo:
Use color code link above to solder wires from radio harness to the adapter harness for your car, as well as the steering wheel control harness/module
Remove trim piece and old stereo
install/modify old mounting bracket for new stereo and plastic single din bracket
Hookup wiring harness and slide radio back in
Configure stereo headunit
Speakers:
Remove front door and rear door molding (best to find instructions on this online for your car)
Remove old tweeters and woofers
Use drill to create new mounting screw holes in door for new speakers
If doing all-in-one speakers - solder wring harness ends to factory wires, attach wires to speakers and mount speakers into door
If doing separate tweeters/speakers - wire factory wires to crossover module, secure module to inside of door or other area, wire module to speaker/tweeter, mount speakers/tweeters.
For sub/amp:
assemble sub(s) into box
decide on amp mounting location
find spot in firewall to run power wire from battery
On one side of the car you will need to remove all of the foot trim boards (plastic between door and where the carpet starts as you get into the car)
Remove kick panel on same side of car (piece to the Left of drivers Left foot or right of passengers right foot)
Route wire through firewall , and all the way to trunk area where amp is at
Route RCA cable AND amp power wire from stereo to amp
Route as short of wire as possible from amp to a good grounding bolt in trunk
Wire up amp with power, ground and turn-on wire form stereo
Wire up amp to sub