Either way, film or paper, give yourself enough time to test to find the right exposure times.
I have done both, film in adapted slr cameras and paper in diy boxes. If going down the large format diy route and if you have access to a 3D printer it is worth looking on the net for 3D printed film holder files. This would give you an easier paper/film change in the field (I bought some cheap in sales but 10x8 holders are never going to be cheap if you have to buy them,) mine are a mixture of half-plate - like 5x7 only slightly smaller, film this size has to be cut down so avoid or use paper - 5x4 and 9x12cm (which are both the same externally and for which film can be bought the right size - but paper is easier, you need developing tools adapted to large format film, diy or bought in).
Testing needs explaining wrt film holders. Most modern film folders (double dark slides etc) hold two pieces of paper/film. This means you can take two shots in the same light with different exposures, which gives a good idea of what your mission critical exposure times will be. It is more difficult to do this with a cardboard box or cocoa tin with one sheet of paper/film stuck in it (elementary but that's how it is!). The only successful pinhole shots I have taken have all been because I tested beforehand. When I haven't I have failed (usually way over-exposed!)