CME British Pound Futures & Options
The GLOBEX symbol is 6B but I'm not sure that's what TradeStation would use. $6.25 per pip.
Definitely you wouldn't want to trade that during Tokyo hours - it moves within a very narrow range. I would be especially careful trading FX during the Tokyo session because it's usually very quiet - just Japanese exporters filling orders - but sometimes banks go on stop hunting sessions are there's a massive and unexpected move. USD/JPY is dominated by the carry trade so the trend is steadily upwards but sometimes the hedge funds will liquidate their carry trades causing a massive drop. Very risky business. Also consider the Australian and New Zealand Dollars which probably have more life at that time of day.