Hi i am looking at a couple of airguns in fac, first is a Webley Spector in .22 with 2 extra air tubes, the next is a fx2000 in .177 running at 17ftp, and the last is a bsa s10 in .177.One is already fac the others would need to be put on fac, what are the pros and cons on each,advice would be most welcome. Thanks in advance Woodydog.