Here's some "food for thought" . . . just keep in mind I'm not a good cook!
Seems to me the off-road crowd actually prefer the older link pin front beam. Keep in mind that it's basically a mid-1930's design. Roads improved over the years and ball joints, a more modern design, replaced the link pins. I've never driven a link pin car as a daily driver but I'm guessing the ball joints offer improve the handling on good roads but sacrifice a little ruggedness. The Super Beetles have a strut front suspension . . . an even more modern design. When everything is correct on a Super it's the best handling Beetle you can get. But, you TOTALLY sacrifice ruggedness. Rough roads will destroy a Super's front end in short order. I've seen Super's with the front part of the body visably warped from one trip off road. Of the three front suspension choices out there, there isn't a good, better, and best . . . it's all a matter of how and where you intend to drive.
In the rear, you have two choices - swing axles or IRS. IRS is Independant Rear Suspension . . . which actually, a swing axle is too . . . but let's not go there yet. The swing axle has an axle inside of a tube that runs out the spring plate. Because there is a fixed distance between the transaxle housing and the spring plate, the wheel moves through the suspension travel in an ark. The IRS has a stub axle running in bearings at the end of the spring plate. The stub axle is connected to the tranny by a pair of drive axles with CV joints on each end. The wheel moves through the suspension travel almost straight up and down. It's kind'a like this:
The wheels on a swing axle car move like this: ( )
The wheels on an IRS move like this: l l
IRS has obvious handling advantages on good smooth roads and in fast, sharp turns . . . but swing axles are tough. VW put IRS in all 1969 and up Beetles built for the US market, but the swing axle was the suspension of choice in the Mexican Beetles right up until the end of production last year. Again, one isn't better than the other. It depends on what you intend to do with it.
On your front suspensions . . . 1965 and back were link pin. 1966 and up were ball joints. Without welding on a new frame head the two won't interchange. A Super Beetle is a breed unto its self. It has a totally different frame head and body actally holds the top of the struts in place. Supers were built from 1971-1979. All convertibles during that time were Supers. In 71 and 72 they had a flat dash and a flat windshield like a regular Beetle, but from 73 up they had a larger curved windshield and a more "modern looking" dash. I believe that Super Sedan production ended in 75 (76-79 Supers were all convertibles). 75 and later Supers had rack and pinion steering.
Although anything is possible if you don't mind cutting, welding, and fabricating . . . keep it simple. Determine what front suspension you want and let that dictate what "pan" you use. I think it's pretty easy to put a swing axle setup on an IRS pan . . . and with a little cutting and welding a swing axle pan can be converted to IRS. It's not an everyday thing, but it's been done many, many times before. As for the actual floors . . . pan halfs are not too hard to replace. Don't pass up a good deal on a car just because the floors are rusted. The bottom of the body (heater channels) are a different story. They are not impossible to replace, but it's not a job for just anyone.
I'm not trying to overwhlem you with information or make it seem like I know it all. I'm still relitively new to all this myself . . . I bought my first VW a little less than 10 years ago. But I made a real big mistake in the begining and I try to help others avoid making my mistake. I had no clue what I wanted, what I wanted to do with it, what the difference between a Beetle and Super Beetle was, etc., etc., etc. . . . then one day I walked into the back yard and tried to figure out what I was doing with 20 junk VWs out there. Having even a slight clue what you want BEFORE you start dragging cars home will go a long way towards keeping your back yard uncluttered! But the neat thing is they are small . . . with a little "creative" parking, you would be supprised how many you can cram into a few square feet.
