1993 525i Touring speakers question

[blackcat1134]

Since I'm 16, excuse the young age, but I'd like to replace the rear subwoofers, since this is a touring wagon, I'd really prefer NOT to have a box in the rear (no real place to put it) So I figure I'd buy 2 8" subwoofers to replace the stock units. I would also invest in a amp. as well.

My true question is, does anyone have any suggestions on what type to buy? I like the boom, but I would still love to hear the music.

Another question is, should I stick with the 2 rear subs or just get a subwoofer tube? Does anyone have any experience in replacing the rear subs?

Thanks! I included a picture of the rear subwoofers.

I just also want to mention that I love my BMW, absolutely the best car on this planet. I know a lot of early drivers prefer trucks/suvs, but in my opinion, one of the greatest cars ever made.