Having spoken I just want to clarify a few points along with your extra thoughts.
1. Best place to buy a bb gun (Best customer service and value for money and reliability)
Any shop without BBguns in the name. BBguns are usualy cheap crap for kids.
2. Deciding between a pistol or rifle- I want something that is sturdy. I especially liked the link to the pistol. I want to get something that is respected. I think most of all I want something that won't break after a few uses.
Personally id choose a rifle, but at the prices your looking at, your not going to get anything thats sturdy, respected or wont break after a few uses. Airsoft is not a cheap hobby, it doesnt have to be super expensive either but you get what you pay for essentally. Up your budget or be prepared to play with crap.
Currently looking at
http://www.onlybbguns.co.uk/hg-104-m92f-beretta-hfc-hg-104-m92-gas-pistol.html?keyword=hfc%20104#.VSpOVtzF-w5
Cheap crap, waste of money.
http://www.onlybbguns.co.uk/m945-gbbp-a-k-m945-gas-blowback-pistol-full-metal.html#.VSpOzdzF-w4
Never heard of it, suprised if it lasts more than a few mags before it falls apart or mags spring a leak
http://www.onlybbguns.co.uk/cm123-cyma-1911-airsoft-electric-pistol.html?filter_val=100#.VSpQuNzF-w4
Personally hate electric pistols, and at that price id much rather go with a decent gas one
would of been tempted by this but its just too much.
http://www.onlybbguns.co.uk/bb-guns/electric-rifles-budget/ares-ar-001-ares-aeg-sa80-l85a2.html#.VSpQ_NzF-w4
Never used an ares SA80 but it will be 1000x better than anything listed above