Hi U2,
I’m a left handed whistle player (2 years) and have recently picked up the pipes (2 months) and play pipes left handed as well.
As has been previously discussed there are pros & cons either way. It will depend on how MUCH left or right handed you are, as well as other factors that you should consider.
My decision was based on the following:
a) playing left-handed just feels more natural and comfortable (for me). I tried playing whistle right-handed for a couple of hours to see if I could really switch. While I proved to myself that I could, I also decided I didn’t want to spend a few weeks or months relearning to play.
b) I’m not too concerned about sharing sets with others (there are only 3 other Upipers in the Atlanta area I know of). While this may change as I get more introduced to the Irish music ‘scene’…right now my main goal is playing for my own enjoyment.
c) playing whistle was a tremendous advantage when starting the pipes. I was able to start playing tunes almost immediately, and took only 2-3 weeks to stop sounding like a sick goose. Therefore, playing whistle left handed and pipes right handed would have been harder for me (by no means impossible, just more difficult in the beginning).
d) the practice set I have is actually made to be right-handed. As previously mentioned the difference is really the key blocks. I sent it to the maker to have him swap the bellows valve around and make a left-handed bag…since the chanter does not have keys, handed-ness is not an issue. Since then, I’ve learned I could have just turned the bag upside down…this would not have given me the same experience, but it could be done if you want to try both left and right handed before investing in a left-handed set.
e) I have a 1/2 set on order which is being made totally left handed (two keys). Only another month or so!! After getting my 1/2 set, I’ll decide if I keep the right-handed chanter or resell it…which brings me to the next thought.
f) Resell is a small concern. There seems to be quite a few lefty’s that play rightey..and only 4 of us true lefty/leftyies. See the poll
http://chiffboard.mati.ca/viewtopic.php?t=15249
If for some reason I decided to get another set, I might have trouble selling my lefthanded set…again, not impossible just a smaller market in an already small market. Like you, I plan to be a diligent student and play for many years…so I don’t expect this to be a problem, but sometimes things change.
g) After getting the practice set with a 1/2 set on order, my wife’s comment was “you know these aren’t like whistles where you can collect them by the dozen.” After 15 years of marriage, I know when to keep my thoughts to myself and decided that a non-committal “of course dear” was the wisest response. :roll:
Part of me is just biased as well. I’ve grownup lefty in a righthanded world and being a bit stubborn (its in my Scottish/Irish/English/German genes you know!) refuse to adapt to right-handed pipes after having to adapt to scissors, tools, etc. 
Welcome to the journey. You’ve come to the right place…just lurking and reading, I’ve learned more about pipes then I could possibly have learned otherwise.
Hope this helps…
Regards,
Gary