What is the best insulation for basement walls?

I want to insulate the basement of my ~850 sq. ft. 1924 bungalow and would like to see what kinds of suggestions might be out there as to how best to go about this. I am in climate zone 7a. The foundation is poured concrete and is in pretty good shape though I do get some seepage when the ground is saturated so that needs to be a consideration.

I have a target of R24 and would like to keep things as simple as possible. I am not thinking of doing the work myself so my choices will depend on what local contractors are familiar with and possibly what is permitted by building code, which would include a vapour barrier on the warm side of the insulation.

Insulating the basement without a frame wall interests me but I’m not sure if it would be possible to achieve R24 without one. Could 2” of EPS with another 4” of rock wool be installed without a frame wall? Even if not required I imagine it may be advisable to protect the insulation with some kind of covering after.

I have also wondered whether my poured concrete foundation wall is flat enough to use an EPS layer as vapour barrier. The poured concrete foundation appears to have been formed with square sheets of plywood maybe a couple of feet to a side and bulges a bit in the middle of each square. Also, I need to ensure that any seepage in the wall can escape so I wouldn’t be able to seal the EPS at the floor. If the EPS as vapour barrier is not advisable then maybe the 6 mil poly with something less rigid as the first layer to press it against the foundation wall would be better. But would that work without a frame wall to hold it in place?

thanks,

Paul