I am not real confident in a short of GTLS right now. Looking at the weekly chart below you can see it just broke above previously set highs to make a new 52week high and there is no obvious point of resistance (supply) above it until you get to the $45 level. However since the recent rally to it's current point was fairly weak, we could look for it to come back down below the upper red line and consider a short at that point (roughly $27.00). If you go short at $27.00 you have 4 potential target points.
1. $22.25- from early to mid-August '09 levels
2. $21.25 - from early January '10 levels
3. $19.00 - from mid-June and again mid-July levels
4. $15.00 - from many base levels
Which target point you pick will depend on the momentum of the stock as it nears each point as well as your own personal strategy and taste.
As far as stocks or options on this one (assuming single option plays) I would probably say short the stock itself with a stop loss close to $30, if you want to play a short. The reason is that for this stock, you only have a choice of buying either $30 strike puts or $25 strike puts and both of those have low volume and open interest and high spreads. Add to the that the Volatility levels are currently a bit on the high side means the prices on the options are probably a bit over inflated anyway so you would be better off just shorting the stock itself. It might be possible to use a credit spread option play but explaining all of these other potential plays is just way too much for me to write on here.
<img src=http://www.fantasydaytraders.com/eqpics/gtls-1.jpg>
