They can restore your originals to original specs. I think it's in the neighborhood of $140, depending on what they find wrong. If you tell them what you have, they can tell you exactly which speakers match OEM. I'm sure I have their part numbers around here somewhere, but I'm thinking the repop front speaker is around $35, and the rear is around $50. If your radio still works, you could use it 'till it dies, or just restore it now. I think they can do conversions, but I haven't gone that route, so I'm not sure. They have done a half dozen radios for me now.
I have one extra original '68 AM/FM I could part with for the right price. They are almost impossible to find these days.
I used to be indecisive. Now I'm not sure. I feel like I am diagonally parked in a parallel universe. 1968 400 convertible (Scarlet) 1976 T/A - 455 LE (No Burt) 1976 T/A New baby, starting full restoration. 1968 350 - 4 speed 'vert - 400 clone (the Beast!) 1968 350 convertible - Wife's car now- 400 clone (Aleutian Blue) (Blue Angel) 2008 Durango - DD 2008 GXP - New one from NH is AWESOME! 2017 Durango Citadel - Modern is nice! HEMI is amazing! 1998 Silverado Z71 - Father-daughter project 1968 400 coupe - R/A clone (Blue Pearl) (sold) 1967 326 convertible - Sold 1980 T/A SE Bandit - Sold