Considering your tight budget and you have mounts to suit Ford, shop around for a cheap AU Falcon XR8 engine with Borg Warner T5. The AU engines even with higher km's are normally still great engines and very reliable.
Plus with the XR8 engine you will still get that old school V8 sound.
With the budget you have in mind, you will need to watch every cent during the build.
Nothing wrong with an LS engine, we run them in the front, back and even sideways now.