CR7000 is the latest model from Sencore and is very very expensive.
The B&K 490 was made in two versions: the original 490 (sometimes called a 490 plain) which used the common "CR" series adapters that previous B&K models used. The last version is the 490-B which uses the totally different "CA" series adapters. B&K discontinued manufacturing rejuvenators two years ago so only used ones are available.
Personally, I have never used any Sencore products because they are way too rich for my blood. I have used B&K rejuvenators and found them to be very reliable and reasonably priced. Any of the models from 467 through 490-B will do you perfectly fine.