Uilleann pipes come in a few pitches. a) Wide bore concert D, Narrow bore D sets
b) Narrow Bore flat pitch C# , C, B, Bb sets. Note there are a few anomolies such as Eb sets and Wide bore C, B etc. and narrow bore G, A chanters. Educate your ear by listening to pipers playing in different pitches.
In this question you are confusing two things, Flat pitch pipes (refers to narrow bore pipes below the key of D, so pipes pitched in C#, C , B, Bb) and Chanter keys (little brass or silver keys mounted on blocks that offer notes outside the major key of the chanter such Fnat, G#, Cnat, Bb ).
I would stay away from bargain uilleann pipes. Save the money and buy the best set you can afford. Do not buy pipes made in Pakistan with no named maker. From what Ive heard from some very experienced pipers I would not hesitate to recommend Makoto Nakatsui of Japan. http://www.nakatsuipipes.com/Pages/default.aspx
If you are serious become a member of NPU an international Uilleann piping organization based in Dublin. Then you will have access to their reed making videos. I believe the is also a DVD available that covers reed making as well called, Heart of the Instrument or something like that.
My best advice is be in no rush. Do not buy the first set you see because it is cheap. Do the homework, read everything available, read every scrap you can from NPU source, uilleann obsession, be prepared to wait for fine pipes. Take your time with the instrument choice, take your time with learning there are no quick fixes.
Good equipment is important.
Just as important is having an experienced piper to set up the reed, trouble shoot your set,
and teach you the basics. Skype might help some what, but face to face is ideal.
Reeds are susceptible to changes in humidity & temperature so advice is to look for a maker where the climate is similar to your own especially when you are along way from other pipers who can lend a hand i.e. a brilliant reed made in a dry hot climate will not necessarily be a good reed in a cold wet one.
Very important to read through the budget pipes thread at the top