I have storage space down either side that I'd like to use for easy-access consumables etc. particularly heavy stuff like tinned food, water containers etc.

There are cables in there and I don't like the idea of snagging the cables when I retrieve stuff. Would also like to prevent damage to anything partcularly the hull when the boat is on its ear, or worse.

I was thinking of lining it with cheap yoga-mat type foam or the like with self adhesive Velcro or something.

Also what's the best way to keep the lids on the lockers without fitting hinges/latches?

Living in Tasmania over the last 20 years I found fibreglass is a poor insulator so I have lined the boat inside (using contact adhesive) with 10mm closed cell camping mats from Kmart.
I have done cable runs with square electrical conduit also using contact adhesive. There is a removable cover on the conduit for access. The conduit is available in different sizes to suit the number of cables

We use Nally bins - they are tough bins designed for warehousing and farming, but my dive gear bin from 1998 is still going strong. Lots of options (although shipping is a bit expensive). nallyplastics.com.au/