I would suspect that any major brand manufacturers are going to be similar in their support of copy protection flags, so Panasonic and Toshiba may not help much. A smaller brand might be a bit less strict in its copy protection.

DVD+R is not part of the official DVD Forum standard; neither is DVD+RW. DVD-R, DVD-RW, and DVD-RAM are all official formats, although very few players support DVD-RAM (Panasonic supports it on all of their players, but that's because their DVD recorders support DVD-R and DVD-RAM only). DVD+R support is very spotty - outside or +R recorders, it's a bit random as to which players can actually play them back.