kit modification questions and help

[purpleyeti]

so i really like hoppy fruity beers. I'm looking at modifying a kit to try and add a bit more hop punch. I'm thinking of using a murtons IPA two can kit and then dry hopping with Nelson sauvignon whole hops as from what i've read they have a strong hop flavour with grapefruit overtones. has anyone done this combination and was it good? Also whats the best way of dry hopping a kit beer.
I know i need to wait for primary fermentation to finish as the c02 drives the flavour off but is it best then to just throw the hops in fv, rack to a secondary fv and throw hops in and should the hops be loose or are they better kept some kind of bag to stop the hops clogging up the syphon when i transfer to a barrel?
I did think of adding the the hops in a nylon bag with some weight in it to the barrel but as i go away with work it can take me a while to get though a barrel and from what i understand the hops can add some off flavours if they are left to long.

hopefully someone can shed some advice so i can improve a few kits before trying something new.

[Rookie]

I'd try this first with a hop I've used before and know I like.

[DeadFall]

I usually brew a few litres short, say 19l instead of 23l and ferment as normal. After a week, I'll boil some hops up in a litre of water for 20 minutes, usually dropping more in at 10 minutes and again when I turn the gas off. When this is cool I'll strain the hops out and add to the brew along with a few hop cones and bottle/keg a week later. Until recently it was just throwing in random amounts of hops. Last time I measured, using citra hops, 10g at 20m, 10g at 10m, 10g at end, and 5g to dry hop. This was for a St Peters IPA brewed a litre short. Smelled wonderful when I bottled it. The remainder of the hops is in the freezer waiting for next time.