Anything beyond 1.3 and you'll probably need at least 1.3 front brakes, if not EFI Vitara or better.
Having said that you will want better brakes anyway for running bigger rubber as 1 litre are not well braked.
In vic you have different rules, but as a rule of thumb a Naturally aspirated 1.6 will be easy (whether it be Suzuki or not is nearly irrelevant) and anything over 2.0 will be much harder. Best to ask an engineer before you try and bolt that V8 in.....
Good options (based on power, size and weight) that have been done before include the Vitara (obviously), Gemini/Isuzu 1.6/1.8/2.0 and 1.8 Diesel, various Corollas (inc EFI 4AGE/4AGZE), Datsun A14/A15 CA16/18 SR20.
Yes some people have V6 Commodores in and approved but it's not a cheap or easy job..... unless you're a magazine editor abusing your position
You should be able to find information about many of these engine swaps here with the SEARCH button.
A few other alternatives come to mind that could be really cheap like Bluebird CA20's - 5 speed as well as whole car for a couple of hundred bucks.
Saw a side damaged injected Pintara go for $300 at auction the other day....
There's a dual transfer cased Gemini/Isuzu motored Sierra in our club with an early 4 speed Jackeroo Gearbox and tcase (bolts on to isuzu engine no problems) leading in to the Sierra Tcase.
It needs some more effort to get right but it has some potential there for sure.... and would have way more with a Holden Piazza Turbo engine instead of an old 1.6 Gemini....