Yes you can play Riichi with a Chinese set. All you need to do is ditch the flowers and seasons.
You will not get the rectangular Oya marker but you can easily use the Chinese wind marker remembering only to use East :east then South :south. Or you can buy them from Hiro\'s website (
http://www.japanese-mahjong.com/windmarker.html) or from Jenn\'s shop (
http://www.mahjongmart.com/shop and click on Other).
If you want to play with Red Fives you can always paint or otherwise mark the tiles. I used Humbrols Ferrari Red Acrylic Paint (#220) to mark up a set of red fives on a Chinese Tournament Set I had lying around.
Japanese tiles are usually smaller. Modern Japanese sets are often Riichi sets with red fives (usually four red-crakred-bamred-dotred-dot) added and 4 seasons (the other flower tiles are dropped). Japanese rules do not use the flower or seasons tiles even if included.
Probably the main consideration is
Are you comfortable reading the Characters suit, and Winds in kanji? If you can\'t read them or don\'t want to learn them then you would be better going for a CHINESE IMPORT version as there are few Japanese import versions with arabic indices around.
Both the Chinese and Japanese sets for the local markets do not have the Arabic indices indicating to the english speaking world. A limited number of Japanese sets are aimed for the export market with indices which will limit your choice if you wish for that style of marking.
Crudely speaking Japanese sets are often of better quality carving and are more expensive. They are also harder to get locally without importing and incurring extra shipping and import duty costs.
Another consideration is size and therefore weight
From left to right: Japanese, American, Hong Kong, and Vietnamese tiles
(from Tom Sloper\'s site
http://www.sloperama.com/mjfaq/types.htm) which has a series of excellent FAQs which if you haven\'t read, you should as it is one of the most extensive mahjong sites on the net and well worth a read.
Having said that I do like the Japanese sets that I have played with.
In summary: (1) how much do you wish to spend? (2) how big do you want your tiles? (3)