Yes, very. Just get an rpm window switch (msd has a very good digital one), one step colder copper plugs and check the a/f on a dyno. A wet kit is great because you can adjust the a/f ratio using fuel pills, not by messing with fuel trims or the MAF curve like a dry kit.
Type in "NX wet kit" into the search feature...read every thread you can. Knowledge is your friend.
yes it should be safe. as stated research as much as possible. do not ever use any platinum plugs. they will foul up. buy as many features as possible. a wot switch, window switch and purge would be some things to invest in. most kits already include the wot switch. the window would be an added safety feature as it only allows the nitrous to spray in a set rpm range. the purge will clear the lines and allow you to recieve 100 nitrous every time.
A wet kit is a good investment if you are only spraying a 75 shot. Like everyone else said, a window switch is a good idea. Another good idea would be a fuel pressure safety switch, so if your fuel pressure drops too low while running the nitrous, it will kill the nitrous. If you wanted to be a real freak about safety, then you could get a wideband commander. It will cut the nitrous if your A/F goes too lean which is an awesome feautre...too bad a wideband commander is $450.00.