Well let's see what I can say
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Well, firstly, if you want a course than concentrates on hardware, then you might want to do the BEng in Computer Systems, as that course will concentrate on hardware. However, being an Engineering degree, it will be harder.
Now, if you are looking for a course which has a greater likelyhood of you getting a job, then pretty much any combined degree will give an an edge over a single degree. So having said that, the BBus/BComp degree will give you more of a chance of getting a job. Mainly because you are technically doing 2 degrees, so you pretty much have the career options of both degrees, as well as careers which require you to have both Business and IT knowledge. If you do the Accounting major in Business, then you pretty much have a good chance of getting a job in one field or another.
Having said that, don't do the BBus/BComp degree if you're not interested in Business. If you're only interested in IT, then the combined degree is not for you, as you won't have much of an interest in it. Only do the combined degree if you like both Business and IT.
The BScIT degree is a pretty good course as well. The job prospects are quite good for this course, as its an IT course related to business and how to apply the stuff you've learnt in businesses. You learn a broad range of IT stuff, like programming, networking, information systems, databases, etc. You learn the same stuff in the combined degree as well. You've also got your DipITPP which is your year of industrial training, which is quite beneficial when you're trying to find a job after you finish.
In my opinion, between USyd and UOW, I'd go with UOW as they have some very good IT courses just like UTS.
So yeh, it all depends what you want to do and where you're interests lie. You can always start off in the combined degree if you want and drop down to the single IT degree after your first year. It's probably easier to go from BBus/BComp to BScIT, rather than the other way around or going to just BBusiness. Transfers are not guaranteed though, so you should try and make the best decision now, and since the UAIs for both courses aren't too different, whichever choice you make, you should hopefully get in.