Tachihara cameras are well made, and if you got it for a bargain price, there are a few options. Extension backs for 8x10 are sometimes available. There are some limitations on lenses and movements, but if you intend using the camera indoors, it might be an inexpensive way to get into 8x10. Similarly, reducing backs for 5x7 and 4x5 can be bought or fabricated relatively easily.
Japanese whole plate cameras tend to be very light and compact, so if you are willing to shoot that format, it can be better than lugging around an 8x10. The size difference isn't very large.
What kind of back does it have? Does the focusing panel swing away? If so, you will need to use bookform holders. These were made for plates, and sheaths for film are available. If it has a spring back, then the usual style film holders can be used, though you would need to make sure of their outside dimensions. There were no specific standards for the holders.
Whole plate B&W film is available from Ilford once a year, or European companies like FOMA, etc.
Kumar