advice on raised border planting please

Hi there - I am having my small garden revamped, with a new (slightly larger) composite deck and new artificial turf ( I have a great dane and that is a lot of scorched grass to deal with!!).  The decking will be a dark grey/charcoal colour and one fascia board high (145cms) and the existing raised beds will be 3 fascia boards high (0.43m high in total).  The garden faces north east so gets sun in one corner in the morning and the opposite corner in the afternoon.  I would welcome any advice on two points:

1.  What evergreens can I plant in the narrow (50cm) borders that will give height, movement and year round interest  (we are keeping the honeysuckle top hedging) and,

2.  How do i deal with the curved end of the decking being 1 board high, and the raised border that buts up against it being 3 boards high?  Will this look weird and if so, any solutions?  The photo shows the rough curve of the proposed decking outlined by the garden hose! Where the hose ends against the wall, will be where the extended deck and raised border meets.