Nick. Welcome to MoveToNZ.
Changing professions while you're about to apply for Permanent Residency isn't a good idea as the NZIS is looking for people who have qualifications and work experience in particular areas. With IT experience and quals you should stand a good chance of getting PR, but I'd think if you made a complete change in your career to something you haven't done before, it could make things very difficult for your application.
Usually, if an immigrant wants to run their own business in NZ they apply for a
Long Term Business Visa . I would normally say that to apply for one of these you would need to have previous experience in a similar field before you could move forward. However, our member,
Macfod , managed to get his
LTBV without previous experience after he'd bought a cafe so it is possible.
You could use your IT skills to obtain enough points to get into NZ permanently and then, once the dust has settled, you could progress with your plan to buy a hostel.