Basically spec me a ready built bike within budget. Want it to be light ish and it’s mainly for moorland riding, Gisburn and Lee Quarry and twisty woodland trails. Looked at the btwin rockrider 9.1 full suss various Cubes in 26 inch and 29er variety.
Merlin Malt, Trek Mamba 29er.
Current bikes a Carrera Vulcan but I just want something new and fresh.
Suggestions please.

Take a look at the Vitus Zircon I or II on CRC as they represent pretty good value at the moment, with either falling into your budget.

Your only a couple of hundred under an on one fatty 😉

Radon ZR Team 7.0 would take some beating at that price (~£730) if you fancy a punt on some teutonic mail order.

No idea about these sellers but:

http://www.bikes2udirect.com/B5281.html

http://www.ukbikesdepot.com/m15b156s776p8064/GENESIS_Mantle_30_Front_Suspension_29Er_Mountain_Bike_2013/RS_GB/24271?gclid=CPG80JPVoLkCFU_MtAodj20Aag

http://www.canyon.com/_en/mountainbikes/bike.html?b=3003#tab-reiter2

Another Genesis Mantle from bikes2udirect.
I suspect you’d have to part build yourself at this price, but if you’re ok with that, they look great.
http://www.bikes2udirect.com/B5601.html

For the money, I reckon

http://www.chainreactioncycles.com/vitus-bikes-zircon-i-hardtail-bike-2013/rp-prod81009

http://www.chainreactioncycles.com/vitus-bikes-zircon-ii-hardtail-bike-2013/rp-prod81012

Finally something with 120mm to challenge the value of the Boardmans Team/Comp or in 29er

http://www.chainreactioncycles.com/vitus-bikes-zircon-29vr-hardtail-bike-2013/rp-prod81010

They all look good. But not sure which I like the German bikes the Canyon but the radons are out of stock.
The Vitus looks good also. 29er or 26. Current hardtail is 26 inch. Have test rode a Cube Analog 29er and that felt nice compared to my Vulcan.