There are several brokers in Singapore and Hong Kong who offer GL, including Refco/Man. I guess the US may be a different game.
GL via brokernet is quite suitable for trading Kospi. Whatever you use, it better have good bandwidth because when Kospi jumps you have serious activity in about 8 strikes plus the future.
The commission quotes are *very* competitive in Asia, but you are right, they are not talking about a $5K retail account.
A $5K account will not be able to trade any Kospi futures because margins are higher than that, and you will not be able to sell any options unless you are already long those options because of the high margins. (Kospi margins working sell orders without considering the resulting portfolio balance)
I dont know where IB get their margining from, but the KSE runs live margining of all positions, including working orders.
I think the absolute minimum to trade Kospi realistically would be about $50K, but thats a bit like microsoft saying you can run XP in 256MB. $100K is more sensible just like 512MB is.
I think the only thing you could do with $5K is scalp the long side of the options, and there are lots of people who do that.
We have been very interested too in IB because they are very competitive in other markets. But with .2% comm on options I think a lot of people will hang back until it comes down. A bit chicken and egg I suppose, but I dont think anyone will want to trade even moderate retail size at that rate.