If you don't find enough people here who've had direct experience comparing a modified CD25 with one of your other choices, it might be worthwhile to at least upgrade the opamps in the CD25 since that's a very easy upgrade to do yourself, no more difficult than changing a fuse.
At least you'd get a better idea of what the CD25 is capable of and you would probably recoup at least most of the outlay if you decide to sell.