I have found deepseek coder 33B to be better than codellama 70B (personal opinion tho).. I think the best parts of deepseek are around the fact that it understands multi-file context the best.
No special flags or anything, just the standard format. Do take care of the spaces and end of lines. sharing a gist of the function I use for formatting it: https://gist.github.com/theskcd/a3948d4062ed8d3e697121cabd65... (hope this helps!)
Straight up giving large files tends to degrade performance (so you need to do some reranking on the snippets before sending them over