I think the bass link has a built in amp.

If you wanna run subs and speakers off the same amp you'll need a 5 channel.

otherwise get a class d for the subs and a 4 or 2 channel a/b

 

Yeah the Basslink II is a 250 watt powered sub. Personally, I think its one of the best powered subs out there. In addition, you can get an additional module for its expansion slots to power speakers, but I don't think its all that powerful.

All the Sony subs i've heard do not produce clear bass.

There's only one deck that I know of that is the 1.5 din size, which is the Pioneer DEH-P47DH

 

I belive the 03 blazer is double din? My dash opening, vertical is 4 inches.

 

Yeah, 4 inch is a DD, but the 03 seemed to have both sizes available. At least according to Crutchfield. How tall is your opening skibby171?