I am for sure getting 15inch subwoofer and here are my options... My goal is to have good amount of spl and high Sq that can hit the LOWS!
My choices i have are

2 15inch Alpine SWS 2012 model in a sealed box.
Single 15inch Alpine type r in a ported box.
Single Re Audio SXX 15inch in a ported box.

The amp i will run my subwoofers is a kicker kx 750.1 but birth sheet is rated at 892 rms @ 2 ohms.

 

Here are some better options (depending on your budget) in a ported box.

GCON-15 Sound Solutions Audio 15" 750W GCON Series Subwoofer - SSA STORE

Havoc 15 Ascendant Audio 15" 1250W Havoc Series Subwoofer - SSA STORE

ICON 15 Sound Solutions Audio 15" 1250W ICON Series Subwoofer - SSA STORE

 

Yeah im on a budget at the moment. I am leaning towards alpine or re audio because i can get them really cheap!

 

In that case, out of your list the alpine type r ported gets my vote.

 

KK thanks, now just gotta figure out box specs that will fit in my car

 

Since your on a budget check out C2 audio, should rape both the re and type-r since jacob from sundown helped develop these
C2 AUDIO || 15" Threatcon-2 Subwoofer

 

Obsidian Car Audio