I used to be into air rifles before I discovered the world of shotguns.
I still have a high power rifle... about 11.8ftlbs I believe. Sent me back about £550. It's a .177, but it still packs a punch like.
If you're serious about getting into the sport, don't buy cheap rifles. That's my only advice. Cheap ones f*ck up. With air rifles, you basically get what you pay for.
Regarding the law, you don't need a gun safe or anything at home, but it's best to keep it out of the way, in a gun slip/ hard case, under a bed or at the back of a wardrobe...
And also, it's illegal to carry an air rifle in public, without it being in some type of case. I vaguely remember it having to be in a hard case if it's not in a car or something, not too sure. You must also have a valid reason for carrying the gun, ie, you may have just purchased it, or are going shooting etc etc.
There are loads of different laws and regualtions to owning an air rifle, and I'm sure if you visited your local gun shop, they'd be happy to advise you
EDIT: as said above, the air arms range is superb wuality and value for money. As it happens, I too owned an s200, although it had a few little goodies attached (multi shot, suppressor, scope etc etc )