Hi Ben,
welcome to the club..
Spring - Baikal 53M & a Gamo Falcon , great value , £40-£50 ish each.
Co2 - Benjamin EB22. About £75-£115 ish. Quite accurate, LOUD and fun.
Gamo R77 revolver - Classic revolver design with a "real" revolving full cylinder (not like them there S&W crap looking one's), £40-£65 ish. look for a 6" barrel.
Got a PPK/S, £50-£70 ish. A great laugh, blowback, smooth bore so not really suitable for Target stuff.
The MP654 is a beautiful looking thing, bit more accurate then the PPK, rifled bore. Uses the real pistol frame. £70-£100 ish.
SSP (single stroke pneumatic) - Gamo Compact. Cracking starter target pistol. £85-£100 ish. Love mine, doubt you'll ever really become too good for this. Look at the UBC scoresheet to see where they come in the SSP section below.
http://www.ubc.btik.com/documents/2227465056.ikml
It's all really about personnal choice, I don't like the modern shape pistols, The only one of them I would look at is the CP88 or Colt 1911. BUT, they are accurate. springers are harder to learn to shoot with, but far more rewarding than the others.
Don't bother buying new mate, there are so many available on here, usually look at paying about 2/3rds the new price for a good condition used.
Hope I haven't confused you too much
atb
Russ
Air Arms S400 Classic - Hawke Airmax 3-9x40 AO MAP6, SMK QB78 DL - JSR 4x40 Mildot ill.El Gamo ASI sniper, BSA Airsporter MkVI. UBC#22 - Sheridan EB22, Gamo Compact:R77-4:Falcon, Walther PPK, CP88 shiney, SMK G10, Baikal 53M:MAK, Crosman 357