If you live in Sydney maybe an Elstar 150? I have one, 17" front 14" back i find the suspension soft at the track but on trails its ok, 150cc (Branded elstar but its probs made by somebody else), Spare parts and headquarters for Elstar is at Milperra so its not too far to go for parts, spares if your in sydney..
Dont get me wrong its not up the pointy end of high "quality" pitbikes but its got a fairly strong motor, the frame is twin spar style and is very strong (I ride mine at appin and I bottom mine out, case it, flip it, you name it ive done it and ive only ever broken a lever.. )
so yeah for your purpose it may be a good choice, obivously if you got one you would locktite everything but also check your fuel lines, 1 of mine was ran right next to the exhaust and it got burnt through, but after i fixed that it was fine.. also put heavy duty tubes in, My chain and sprockets have held up reasonably well so depending on how much you ride it i wouldn't bother changing them, also the gearing is good in the bush, at the track its a bit high and needs more bottom end but in the bush its spot on..
heres a pic:
Hope this helps..
edit * 1500 brand new but I talked mine down to 1370 with pro taper bars and grips, P.S get pro taper bars n grips the stock ones are not a good bend..