Run and bike gear in Bangkok?

I know....I should post this on the SE Asia forum, but there hasn't been any action there for over three months, so thought I'd try here. I'm heading to Bangkok for a conference next week and in the market for some sports-related items (due to poor planning/packing in August). Ideally--some running shoes with really good drainage for training in rainy season (mine are all sponges), a light windproof/rainproof jacket for cycling, cycling knickers (for a possible bike tour in December that may get into some cooler climes), more electrolyte tablets (if I do the winter bike tour, I won't be hitting a developed country again until February, thus the need to stock up as I can't buy the tablets or powder locally).

I'll be staying at the Holiday Inn near the Intercontinental on Ploenchit. Not that familiar with Bangkok but on the map it looks like Amarin (sp?)Plaza is right across the street and the complex of malls at Siam Square not far down the road. (Plus Lumpini Park about 1 km away so maybe can squeeze in a run super early.) Won't have much time and also have some non-sports-related shopping to do, so this needs to be high-efficiency shopping. I can check online but would appreciate it if anyone knows of a good store(s) that reliably has western size stuff--I can probably fit a larger Thai size for clothes but wear women's size 10 shoes. I remember Bikezone from last time I went and think they would have the electrolyte tabs, but can't recall if there were any clothes there.

Edited by Hot Runner 2014-09-21 2:29 AM