Is it a bad/good idea to cut the bottom of the doors to mount speakers in...

[oldblue1968chevy]

Well, my speakers were in lil cheapo plastic boxes glued to the floor..but I took those out, wanna have a lil 'cleaner' look...my options are put em back under the seat,cut the doors (i think the cleanest) or kick pannels....I really wanna cut the doors but i dont wanna mess up the speakers, or the sound of em, by puttin em in the doors...

and i i do put em in the doors, should i put em in the pannel that comes out, or the door frame in the VERY BOTTOM of the door, and should i use 6.5 6x9 or like 5 1/4 speakers, thanks!

and not really lookin for base..just some ok music..I'll put some subs where the gas tank is now EVENTUALLY that'll be my base