This winter I am planning on re-upholstering the front bucket seats in my 67 convt. I have looked at the Legendary catalog, who is supposed to be the leader in interior, and I have seen foam padding from the brand OER. Is there any difference between the two brands besides a very wide price margin? Also are there any other brands that are of high quality besides these two?

I also did some searching for these. I found an outfit called TMI that does an updated version of the First Gen. seats. But.... they seem to be specific to Camaro. I mailed them and asked about removing the "Bowtie" emblem, that is not a problem. Also asked to insert the Pontiac emblem.... big problem:) The deluxe seat package looked really good to me, but I decided to go a different direction.
I found them at Bowtie classics......... I don't know if it is allowed to mention business names, especially concerning bowtie

I used PUI interiors years ago they fit really well and looked great. The quality of the seat foam is the key to a good looking seat.... PUI has a web site so check them out. The legendary is new to me but the company i bought my covers from now sell legendary so they my be the next best. The seat foam came from American Cushion Industries in Shelton Washington. They do have a web site check them out i think they are the best.

ACI seat foam is excellent.

For a firmer seat, use a piece of burlap on the new seat springs, followed by a piece of thin composition carpet padding (the one made of scraps that is very firm), a layer of batting, a layer of cheesecloth, and finally the seat cover. This will give the feel of a modern seat without affecting the styling. You can pad out the bolsters on the sides of the seat covers with cotton batting (looks like felt) so that they have some definition, and be sure to wire down the listing wires to the seat spring frame for proper appearance.