HP Pro 120 XXL (Zoll. extreme?) - specs

Hi everyone,
i'am looking around for components to make an audio system for my bass guitar, i found the amplifier (http://sound.westhost.com/project27.htm) which i can assemble it myself and now i'am looking for the speaker(s), so today i found this "Hp Pro 120 - XXL" at a good price, but i never heard nothing about it, its probably used only in cars or its not diffused too much here in italy, according to google this is the unique website on the inet talking of xxl (zoll extreme ?) and fs vas qes etc, so i'am here trying to get more infos about this speaker from this community which seems technically skilled, going to the questions:

Do you know this company ? (XXL xoll extreme)

How do you rate it for the scope that i'am trying to reach (A musical instrument is much more dynamic than an hifi) ?

Do you know this woofer, you can tell something about it ?

Do you know, or you know where i can get the Thiele-Small specs of this woofer (i've to make the box for it) ?

The seller of this item rates it as 500 watt, but as we know much people tends to enhance this parameter So do you know if it can play fine with an amplifier of 100 watt (the one in the url that i wrote before) and with the dynamics of an instrument at this power ?


Regards.

P.S Please reply in english if you can.