I used to own the Cambridge set-up you describe (for many happy years!!) and still own the CD player.
I'd highly recommend the Cambridge set-up, but you do need to be careful when partnering speakers. If you spend your money wisely on speakers, you'll have a super system.
The Cambridge's presentation is fast and very detailed, so rhythmically they draw you very much into the music. They're also excellent for classical music. Their potential Achilles heel if wrongly matched with speakers is that they CAN have a tendency towards brightness in the treble. This is where speaker matching is so important. I used to partner the Cambridge system with Ruark Epilogue II's. They also majored on speed and detail, but with certain types of music (notably anything with quite screechy electric guitar, or poorly recorded music), they could sound over-bright.
So as long as you partner with speakers that are also rhythmically fast (so you don't lose this strength of the CD/Amp) but have a slightly rounded off sweeter treble, then you'll have a system that will bring big smiles to your face. I'm a big Radiohead fan (mainly their new electronica style stuff), and their well-mastered but complex layered sounds sounded absolutely awesome on the Cambridge system - much better than I would have expected in that price bracket. Anything with any kind of foot-tapping rhythm, percussion and acoustic guitar, again sounded jaw-droppingly good.
If I were you (and I'm obviously not) I'd snap up the Cambridge and spend your money on some fab speakers that'll squeeze the very best out it. FWIW I believe the Marantz set-up has rather similar traits (of speed and detail but airing toward a harsh treble if partnered badly), so if you did go the Marantz route, you'd probably need to look at quite similar speakers anyway.
Any decent hifi shop near you should happily let you take the amp and CD in and demo a range of speakers. I'd strongly recommend you do this. I'd also recommend good quality copper speaker cable - steer away from silver cable which exacerbates the treble weakness I mentioned.
Let us know how you get on. Hope you find something that brings as many smiles to you as the system did to me!