My suggestion is to make them aware of all the possibilities involved in Shadowrun campaigns, may it be in problem solving (some are easier to solve with different skills), type of jobs that can be offered and the like, before you continue your preperations. Ask them if they still want to play these characters as they are. If they do, DO NOT PUNISH THEM for creating characters they like. That would be just lame. If they do play these characters, these guidelines may help you in dealing with them.
-Fixers choose jobs best suited for the team.
-Put obstacle more easily dealt with either social skills or stealth based skills but do not ever make them impossible without them. Optional objectives are another matter tho.
-They want action, give them action.
-These jobs are fairly suited for your team (some with maybe just a few skills acquired with karma), without too much difficulties: Package transport and delivery, VIP protection and escort, Vermin extermination (do not underestimate the size of the rats in Redmond), Thug/Intimidation, even Smuggling if they have in either smarts or social skills what they lack in stealth skills.
-With good preparation and good equipment, they can do things they wouldn't be able to normally.
-They, or the Fixer, can hire outside help if needed (see pre-made NPCs or you can make your own.)
That should cover what I had to say to help you on your first Shadowrun Campaign.