Take a look at these... http://www.shureidousa.com/kobudo/tunfat...
Note: the square ones are a little easier to control. when I was learning my Sensei at the time had me order the round ones because it made me work harder.
Another site for really custom made Tonfa and other wood weapons is at crane mountain
http://www.crane-mountain.com/styled-3/s...
...
If you absolutely have to the first one. Don't get any funky shapes (unless you plan on funky techniques that don't work to go with the funky Tunfa) as this will affect the balance and there is nothing worse than poorly balanced Tunfa or shapes that make it difficult to stop/catch the weapon. There is a reason traditional Tunfa are shaped the way they are. What I don't like is that they do not give you any choice of length. So make sure that they are the correct length for you. Also the handle is way too big and you will definitely be struggling with the weapon as in having difficulty controlling the weapon. I had a pair like that and do not use them at all anymore because they are just a pain in the @$$.
If you know someone who works with wood have them custom made with correct length and handle size. It is so much worth your money.
Shureido is also good. I haven't looked lately but they only offer different lengths, not different handle sizes. If you hands are smaller this may be a problem still. Other than that Shureido are really good.
I would go for the 24 inch fiber glass police tonfa because it is the longest one. I have seen fights between two people with tonfas and the one with the longer tonfa won. If you feel that the 24 inch one will get in your way, then buy the collapsible one.
i wouldnt get any of them either. they are not a good quality
i get mine custom made now so besides the link pugpaws gave im not sure of any good brands. its been a long time since i bought from a pair that wasnt hand made.
btw the length should be an inch passed your elbow. as liondancer just stated those others dont give you a choice in length. they make it more difficult to use if its too long
http://www.swordsknivesanddaggers.com/martial-arts-black-tonfa-set-of-2-20-inches-1230.html
http://www.swordsknivesanddaggers.com/fiberglass-police-tonfa-2207.html
http://www.swordsknivesanddaggers.com/aircraft-aluminum-expandable-baton-tonfa-2297.html
Learning how to use them, but first I'll need to buy one first.