help with replacing speakers

Recently inherited 95 Avalon. All 4 speakers are blown. I have a few questions. I took the door panel off and from what I can tell the factory speaker is 4 ohms 20 watt max. Is there any new speaker which is a direct replacement, does anyone carry a mounting bracket for a new speaker to fit. Is drilling new holes the only option. Also does anyone know if there is a factory amp for just the basic sound system. Will i need any additional equipment, amp or new headunit which is absolutely necessary for the install. thanks.

If the radio is OEM you can only replace w/ OEM. If you go aftermarket, you'll have to get everything, Radio, amp and speakers. I have the same problem and am trying to locate OEM replacements from my junk yard. Much cheaper and the sound is good for me.