Mahjong Time is offering Credit Cards , echeck and paypal as payment solutions.
At the moment I cant find there the $100 sign up promo anymore
but I see they have many new ongoing promtions.
terms can be found at each promotion.
Just go there and click on the "PROMOS/NEWS" button at top of their homepage.
A wire transfer is mostly possible at almost all online gaming sites.
Also Check should be ok.
But the very best at many Skill gaming sites is that you can use paypal.
Paypal does not allow to transfer funds to online casinos , they dont allow it for online gambling, but Skill is NOT gambling.
This is why Paypal is an option at many SkillGames Sites.
Hope this helps you a bit.