Advice for an Astra Militarum killteam

[spongezilla867]

Hello to all , I am wanting/started to get an Astra Militarum killteam going. I am very new to this and currently have a pack a cadian shock troops. What else would I need to purchase to make a complete Killteam?
In the cadian shock troop box I have the options for flamer, grenade launcher, comms, plasma and melta. Which 3 would be the best to choose from those options?

[harryf]

wahapedia.ru/kill-team2/kill-teams/imperial-guard/

Based on this source, it would appear that to do a guardsmen kill team, you would need at least 14 models (2 fire teams of 7)

Those more experienced than me can weigh in.