General advice on set-up etc please

Hi there,

I'm based in London, UK & am returning to the fold after 30 odd years & have (almost) put together the following:

Luxman M-2000 & C1000, Denon DP-60L & Luxman T-110. The speakers are fairly recent high quality "bookshelf" - can't remember what (!) as they're in the attic...

Questions:
1. Cartridge - MM or MC? I don't want to over invest but do want to do the system justice - is a budget of $750 reasonable? Are there any stand out options?

2. Interconnects/speaker cables/mains - a bit of controversy on this topic i think :) I have Linn stuff from a previous system & assume this will be ok?

3. The equipment needs to be integrated into a wall unit (yet to be built) so I can't (& don't want) to use a floor-standing equipment rack. Are there proprietary wall mounting systems out there that are recommended? How fussy do I need to be about placement? Can I stack some of the components? should they all be on wall-shelves?

Any help would be much appreciated...

Thanks, Stephen D