Done both, Foam is expensive and short working time and heats up when curing, best to have the manf come out and do it (if avail) that way they eat the material if they screw-up.
Bead kits I get from GARVIN motorsports (Fla) they come with EVERTHING needed except the driver,seat, vacuum. working time is long so you can spend time getting it right, and you will need somebody to work the material while you sit (go to the bathroom first) and you will be sitting for a couple hrs with the vacuum on. Its a 2 day deal , 1 afternoon to mix, fit and set, the next day when cured, do the final trim and shape, and then the cover and tapeing.