I am trying to buy a modern amp which would sound as good as or better than the old Kenwood 3020 SE for around £150 brand new any idea's to match hopefully a Nad 515BEE CD.
Why would you want a new amp for £150. Your best option is a second hand amp that was worth much more.
I personally like the Marantz PM66KI (was £400 new and won many awards), and it is leagues ahead of the kenwood, I know this as I own 3 66KI and also the 3020SE.
You can pick the pm66KI up for approx £100 on ebay in full working order, leaves a bit of cash spare also