I'd start with a big (ish) system, say 150 to 200L batches,
if setup right you can still do 1/2 batches, it's not a lot more money to build a big reactor than a small one.
If you start small you'll end up wanting a bigger one sooner or later (it's a man thing).
But the biggest thing to remember is, oil collection is to be done to the West, around 10 miles from you.
If you end up with more oil than you need, we I will help by removing it FOC.