Are you planning on developing your film yourself, or sending it to a lab? If using a lab, the cost of the film will only be a small part of the total cost and there is no great need to buy cheaper film.
Any film between 100 and 400 ISO sold by Kodak, Harman/Ilford/Kentmere, FOMA, Arista EDU, or UltraFine would be a reasonable choice. Avoid specialty films such as Ilford SFX or any slower than 100 or faster than 400 film - these tend to be less forgiving. Shoot at box speed (the number printed on the box) until you have a good reason to do otherwise.
I personally don't do street photography, but would recommend a fast film such as Kodak TX400 for this (HP5+ is a reasonable alternative, but I personally prefer the Tri-X look). From what I can see, your camera has a maximum shutter speed of 1/1000s. For landscapes in bright sun, this would limit you to f11 or f16. That might be OK for you, but I prefer somewhat wider apertures and would recommend Ilford FP4+ for that (Kodak TMax 100, Ilford Delta 100, Kentmere 100, Fomapan/Arista EDU 100, and UltraFine Xtreme 100 are good alternatives)