Hello,
In regards to the snap deal I recommend what Scott says about learning it from Lennart himself. The best description from him is from the Lennart Green Masterfile DVD's. It is the greatest hits of Lennart Green, it covers everything from his FISM act to the miscellaneous stuff that you would never expect him to do; however, it costs at $150, if you just want to learn the snap deal this may not be the best solution. The next best thing is the Green Magic Tapes, I believe he goes over in two different tapes.(vol 1 and another one) Volume 1's explanation is more in depth than the other but both have valuable information. The best advice I can give if you get Lennart's dvd's is learn the basic mechanics then watch how he does it in performance. There are some subtle details that he never covers in the explanation. I would only get the penguin lecture if you are truely a fan of Lennart. It has useful information but you can tell he gets tired and it causes the explanations to be a bit vague.
His student Takumi Takahashi also a good source to learn the move. I highly recommend the dvd he did with Osmand Magic Bar, called Rentatsu. He covers everything from hand placement and the retention to lateral palm in such detail. It acts as a sequel to the Study on Lennart Green from Shin Lim; however, he admits in the DVD that he never talked about the motivation for the snap deal nor the Laser Deal routine. The DVD is only sold in Japan but Osmand sells it on their website.
In my honest opinion, Lennart and Takumi is a better source than Erik. Erik learned the move from the small booklet and learned the details from watch recordings of Lennart performing. Takumi is Lennart's only student so if you want to have a proper teacher for the move that is affordable, I'll learn from him. Lennart's only in depth description of the move is in the Masterfile DVD. The Green Magic Tapes cover the move briefly due to him still wanting the move to be a secret; however, if you saw him lecture live he went into more in depth.
Here is a list of the sources I mention above:
Lennart Green Masterfile $150
Green Magic Tapes:
1)
Meir Yedid Website $120
2)
Ebay : I recomend keeping an eye on ebay you can sometimes find the individual Green Magic dvd's at a affordable price
Rentatsu : 4000 yen = $26.88(current yen to dollar conversion rate)
Fun Fact: when Guy Hollingsworth saw Lennart Lecture in London, he was able to get the snap deal down immediately. When Lennart published the Snap Deal booklet he wrote, "Guy Hollingworth: Who executed the move, almost immediately he saw it, before I had the chance to explain it. A terrifying experience"