Hi,
There isnt any age restriction in kendo so you can join regardless of age
Since i cant post the URL for singapore kendo, do a search on yahoo or google and you will find it

Apparently the new beginner class has started so you can check about it
most likely they will tell you to go for an interview next year around march (yes, interview =\)
The clothes cost around 100 odd depending on where u get it, somewhere cheaper and some more expensive, search around though there are local suppliers
the armor, at the cheapest i have seen, cost around $400 odd and the bamboo swords around... $50+
Of course there is sports chanbara but i am not sure about it
Cheeros