I need to replace the front door speakers on a 2004 Jeep Liberty. What I have read online is a little confusing. I know I need 6.5" speakers but does it matter exactly what kind?

Some places said you need xx speakers or the top dash / rear speakers will stop working.
Another said to use speakers that come with a pre amp (I guess because the Liberty speakers have an amp attached to each one?)
And some place said any old 6.5 speakers will work.

Thoughts?

Another option would be to buy an OEM replacement off Ebay, but those are $70.00 each.