I've bought a little 100w sub, and am going to buy another 900w sub, and am currently buying a set of 300w 6x9s.
Should I hook the 300w 6x9s and the 1000w total sub power to a single 5 channel amp?
no do not hook all of them to the same amp. You will want to buy two seperate amps.For your car speakers if you just want to but a amp on your 6x9's and not ur door speakers then get a two channel amp with the rms rating close to that of your 6x9 (dont get one with 2 many watts because after about 65 rms to the highs most reasonable priced 6x9's distort really bad. For the sub i would get one that is close to the rms rating of the 900w sub. Do not keep that 100 w sub and put it to the same amp as the 900w (which you probly already knew that it would blow). if the sub you are about to get has a rms rating of 900w then i would recommend the kicker zx1000.1 but that 900w sub would have to be 4 ohm to run it right with that amp.
I hope this helps. if i made a mistake misunderstanding some of the information send me a message or email me and i will be glad to help
Kicker ZX 750.1 class D mono car amplifier, CAR AUDIO STEREO MONO BLOCK MONOBLOCK CLASS D 5200W POWER AMPLIFIER/AMP + REMOTE, POWER ACOUSTIK D1-2000D CAR AUDIO MONOBLOCK MONO 1CH CLASS-D 2000W AMPLIFIER/AMP, DTI MA-5001SB CAR AUDIO STEREO MONO BLOCK MONOBLOCK CLASS-D POWER AMPLIFIER/AMP, POWER ACOUSTIK OVN1-2000D CAR MONO BLOCK MONOBLOCK CLASS-D GOTHIC AMPLIFIER/AMP, POWER ACOUSTIK D1-2000D CAR AUDIO MONOBLOCK MONO 1CH CLASS-D 2000W AMPLIFIER/AMP, DTI MA-5001SB CAR AUDIO STEREO MONO BLOCK MONOBLOCK CLASS-D POWER AMPLIFIER/AMP, Rockford Fosgate PBR300X1 300 Watt Mono Block Car Amplifier For Subwoofer & Bass, BOSS AUDIO PH5000D 5000W MONO D Car Amplifier + 4 Gauge Amp Installation Kit, NEW JL AUDIO JX1000/1D 1000 WATT RMS CAR MONOBLOCK AMPLIFIER MONO CLASS D AMP, INFINITY REFERENCE 1600A IN CAR AUDIO MONO BLOCK MONOBLOCK CLASS-D AMPLIFIER/AMP, KENWOOD KAC-9105D CAR AUDIO 1CH MONO BLOCK MONOBLOCK CLASS D 1800W AMPLIFIER/AMP, New RE Audio XTX5000.1 5000 W Mono Block Car Stereo Power Amplifie AMP, Kenwood KAC-719 Mono Block Car Amplifier. Used. Works. LOOKY!!, New MA Audio 1600 Watt Car Amplifier Mono Block Sub Amp, EARTHQUAKE SOUND PH2000W/D1 MONO CLASS D POWER DIGITAL CAR AMP AMPLIFIER, ROCKFORD FOSGATE P500-1BD 500W AMP MONO CAR AMPLIFIER, NEW PLANET AUDIO AC4000.1D 4000W MONO D Car Amp Amplifier, Kenwood X500-1 eXcelon Mono 500-Watt Power Amplifier / 1 channel Car Amplifier, KICKER DX1000.1 CAR STEREO MONO CLASS D SUB 1000W AMP 2011 SERIES CAR AMPLIFIER, ROCKFORD FOSGATE R500-1 500w RMS MONO CAR AMP Brand New, KICKER IX500.1 500 WATTS 1 CHANNEL MONO AMP CAR AUDIO, HIFONICS HFi1500D 1500 W Car Mono Class D Amplifier/Amp, ALPINE PDX-M6 600W CAR AMPLIFIER MONO BLOCK CLASS D PDXM6 SUBWOOFER AUDIO AMP, ALPINE MRP-M500 CAR AMPLIFIER/AMP CLASS-D 500W MONO BLOCK MRP-M500 BRAND NEW, 2011 KICKER ZX400.1 400W Car MONO D Audio Amplifier Amp, Kicker Zx300.1 300 Watt RMS Mono Block Car Audio Amplifier Amp 11ZX3001, ALPINE MRX-M55 CAR AMPLIFIER/AMP MONO BLOCK X-Power 550WATTS MRXM55, MEMPHIS 500 WATTs SR1.250 CAR AMPLIFIER MONO BLOCK (BRAND NEW) FAST SHIPPING !!!, ROCKFORD FOSGATE P300-1 300 Watt Car MONO A/B Amplifier BRAND NEW CAR AMPLIFIER, SOUNDSTREAM P1.210 MONOBLOCK CLASS AB POWER CAR SUBWOOFER AMPLIFIER W/ BASS KNOB, Alpine MRP-M350 Mono Car Amplifier, ALPINE MRP-M500 CAR AUDIO MONO AMPLIFIER AMP 500W, NEW JL AUDIO 1000/1 v2 1000-Watt CLASS-D MONO BLOCK CAR AMP w/ R.I.P.S. 1000/1v2, KENWOOD MONO SUBWOOFER CAR AMPLIFIER 1200W X1200M X1200MB, CAR AUDIO STEREO MONO BLOCK MONOBLOCK CLASS D 5200W POWER AMPLIFIER/AMP + REMOTE, Kicker 11ZX1000.1 1000W RMS Mono Car Amplifier Amp ZX1000.1+Free Installation, Kicker ZX1000.1 ZX Series 1000 Watt RMS Class D Mono Car Amplifier Amp 11ZX10001, ROCKFORD FOSGATE R1200-1D 1200W MAX CAR STEREO 1 CHANNEL POWER MOSFET AMPLIFIER, ALPINE MRP-M1000 CLASS D 1000W RMS MONO CAR AMP, Excellent CONDITION, MB QUART DISCUS SERIES 1 CHANNEL 1000W RMS CLASS D MOSFET CAR AUDIO AMPLIFIER, POWER ACOUSTIK GOTHIC SERIES 500W RMS 1 CHANNEL CLASS AB MOSFET CAR AMPLIFIER, Planet Audio AP1000D 1000 Watt Peak 650 Watt RMS Mono Amplifier Car Audio Amp, JL AUDIO 700W MAX SINGLE 4 OHMS W1V2 SERIES 13.5" CAR STEREO BASS SUB WOOFER, JL AUDIO 13W1V2-4 SINGLE 4 OHMS 13.5" 700W MAX CAR STEREO COMPONENT SUB WOOFER , POWER ACOUSTIK GOTHIC SERIES 3700W RMS CLASS D 1 CHANNEL MOSFET CAR AMPLIFIER, POWER ACOUSTIK GOTHIC SERIES 750W RMS CLASS D 1 CHANNEL CAR SUBWOOFER AMPLIFIER, REFURBISHED CADENCE ZRS-9 CLASS D 4000 WATT COMPETITION MONO BLOCK CAR AMPLIFIER, Infinity Reference 1300a Class D Mono Amplifeir Car Amp, NEW 2010 KICKER ZX400.1 400W MONO D Car Amplifier Amp,