Don't buy from any website with 'bb guns' in their name. HFC aren't a very good manufacturer either.
WE are good for the price and the best companies are Tokyo Marui and KWA in my opinion.
There are a lot of good airsoft websites but I would recommend Patrol Base, Zero One, airsoftworld, Pro Airsoft Supplies and Land Warrior Airsoft to name only a few. That's not to mention the websites that you can buy gear from like Flecktarn.co.uk, Military 1st, UK Tactical and Tactical Kit.
I completely agree with Monty though, it's better to buy a good rifle if you're a beginner. The G&G Combat Machines are great quality beginner guns. The reviews speak for themselves!
Alternatively, UMAREX guns such as the H&K UMP45 or S&T G36C and are good too.
http://www.zerooneairsoft.com/product_info.php?products_id=5645
http://www.zerooneairsoft.com/product_info.php?products_id=6076
http://www.patrolbase.co.uk/Airsoft-smg/h-k-umarex-ump-45.htm#.U1gLBfldXWg
http://www.patrolbase.co.uk/airsoft-g36-variants/1-hk-umarex-g36c.htm#.U1gLM_ldXWg
http://www.patrolbase.co.uk/Airsoft-smg/asg-BT5-A4-MP5-A4.htm#.U1gLJ_ldXWg
Hope this helps, and welcome to the forums!