Anyone can own any of the ham equipment, amplifiers etc -
Rf Amplifiers are illegal to have at your CB station whether hooked up or not unless you have a license to use one. The rules are clear on this. This falls into the possession category at your station which is not quite the same as owning one. The FCC can't regulate what you can own, only what you use at your CB station.
Look up part 95 rules from any source you want and read for yourselves.
RULE 11 - Linear Amplifiers
{A} You may not attach the following items (power amplifiers) to your CB transmitter in any way:
[1] External radio frequency [RF] power amplifiers, also called linear amplifiers, or linears; or
[2] Any other devices which, when used with a radio transmitter as a signal source, are capable of amplifying the signal.
{B} There are no exceptions to this rule and use of a power amplifier voids your authority to operate the station.
{C} The FCC will presume you have used a linear or other external [RF] power amplifier if-
[1] It is in your possession or on your premises; and
[2] There is OTHER EVIDENCE that you have operated your CB station with more power than allowed by CB Rule 10.
{D} Paragraph C above in this section does not apply if you hold a license in another radio service (Amateur, etc.) which allows you to operate an external RF power amplifier.
Get your Ham license then you can legally posess a RF amplifier at your station, just unhook it if you get Uncle C. Knocking at the door!