Part of why it's pretty hard to answer is that the development is a question mark here; some combinations between developer and film work magic, some result in negatives that aren't particularly exiting. I'm far from an expert, but having used a number of different developers with some films, the differences can really be quite noticeable. Just a simple example: my standard go-to is HP5 with HC110 as developer; while it's supposed to be close to Tri-X, somehow I never got pleasing results of Tri-X in HC110 (probably my fault, but still). In reverse, HP5 in Rodinal was an experiment I'll never repeat, while I quite like the look I get of Tri-X developed in Rodinal. If you have the development done by a lab, then it's harder to say which film will work and which not - unless you can specify to them how you want development done (but doing it yourself is probably cheaper, more fun). Another question that is probably difficult to asnwer: if your friend is loosing his interest in photography, do you feel trying new films is going to pull him back in? Especially if films are so expensive in your country, before spending a nice sum on various emulsions, I'd try to understand first whether your gift would really make your friend get back out and shooting. Another thing could be to get him a basic starting kit to develop his own films, if he does not do so yet - personally I think it's a nicer "extension" to getting him involved in B&W photography. Just some ideas, maybe they apply, maybe they don't.