Go for brew in a bag.
Avoid kegs like the plague, terrible idea unless you have a grand in cash spare.
If you aim at 30l pots your just under the 40 pint 25 litre ish mark. Aim for the 35 to 45 litre pot size and a kettle element to heat it. At the 40 l pot size i do whole water volume biab batches.
I went plain second hand 50l pot, plus gas a gas cooker top, i used two gas rings at once.
I then added a front tap point.
Third was a kettle element and then home made pid controller.
Added a second element and changed the controller box to a twin set.
Fourth was a pump, hoses and clamp fittings. I went camlocks and not tri clamps as i only buy two at a time. Apair with every restock order.
This christmas i went mad and brought 3m of hose pipe!!!!!!!!!!!!!
I still use bottles to hold the beer. I started with newcastle brown ale bottles as thats my only shop brought beer, crown caps are very very cheap to buy for them. some bottles were reused several hundred times. I fell onto a huge amount of Grolsch bottles a few years back and only use these now/ three crates to a brew. i was up one crate a day. Tues, Wed, Thurs. they are sat then waiting for saturdays brew day.
I brew a huge amount of beer and wine, far more than the average hobbiest and do so with simple kit and not millions spent on shiney toys.
Buy something simple but is expandable, a simple pot with do and a mesh bag with hold the grain.