Would these speakers work?

I have a 1997 GMC Jimmy with an aftermarket stereo, and I need to buy some new speakers. I believe I need 4x6 in the front doors and 6.5 in the rear doors. Could anyone confirm this? I was going to try these out:

Front:
http://cgi.ebay.com/MTX-TDX4602-THUNDER-4x6-INCH-COAXIAL-SPEAKER-NEW-10076_W0QQitemZ160279584144QQcmdZViewItem?_trksid= p3286.m20.l1116

Rear:
http://cgi.ebay.com/NEW-2-MTX-XT603-6-5-260-Watt-3-Way-Car-Audio-Speakers_W0QQitemZ220282458298QQcmdZViewItem?hash= item220282458298&_trkparms=72%3A1163%7C39%3A1%7C66%3A2%7C65%3A12%7C 240%3A1318&_trksid=p3286.c0.m14

They may not be the best, but I have heard good things about MTX and I am just trying to replace the non-working speakers. Will these be compatible with one another, etc? I don't know much about the topic.

I assume you have a four door. You need 4x6's for the dash and 6.5's for the front and rear doors.

Ah, thanks..I just need door speakers so I will buy two 6.5's