Amazon.com: Soundstream TA1.3000D Tarantula 3000 Watts RMS Mono Amplifier with Bass Knob: Car Electronics
RMS Power 4 Ohm: 800 W x 1
RMS Power 2 Ohm: 1,400 W x 1
RMS Power 4 Ohm Bridged: 2000 W x 1 (1 Ohm)
RMS Power 1 Ohm: 3000W x 1 (.5 Ohm)
300 bucks new/shipped
i'd go with 2 beefy 12s or 3 solid 10s, since airspace is one thing, but you really need extra room for port area too. 3 tens still have more cone area then 2 12s.
09 Sienna Subs : 4 hdc3 18s c pillar below windowline Sub amp: ampere tfe 8.0 at half ohm.
Headunit: Pioneer 80PRS Mids/Highs amp: PPI 900.4
Front stage: 3 way active front stage with Massive Audio CKX tweets, alpine type R 6x9 midrange in doors + Crescendo PWX 10s in the kick
320 amp Singer alt. 1 group 34 under the hood 6 group31 agms in the back 560 amp hours total.