Unless you are deadset on getting the 16 gb model and you're prepared to wait thru numerous potential delays, then I would suggest you buy from House of Dap. I bought the sflo2 (3rd batch) from Mp4 Nation and the Teclast T51 from HOD. The wait time for the sflo2 was nearly unbearable, while HOD sent right out. I think that the stock headphones that come with the Teclast T51 from HOD are better than the ones with the sflo2 as well. As far as the "freebies" that come with the sflo2, well let's just say that I'm still waiting on my FM transmitter and free leather case that were (as far as I can tell) sent out 3-6 weeks ago.... So, if potentially long (and very frustrating) wait times are not a problem for you and you feel you must have the sflo2 16 gb, go with MP4 Nation, otherwise I would HIGHLY recommend HOD. By the way, both models perform the same in terms of sound quality. I do feel however that it was easier to upgrade from firmware 2.20 to 2.30 with the Teclast than it was with the sflo2, but I was eventually able to fully upgrade both. Good luck with your decision, and believe me, you will love the sound quality of which ever one you purchase. Oh, it is true that the Teclast 8 gb costs more than the sflo2 8 gb, esp with the preorder sale price..., so you should also consider this in your decision making. Both MP4 Nation and HOD provide free standard shipping.
I guess its different for everyone mine took two weeks to arrive and that was everything I ordered including freebies, if its all in stock it should be sent out in the same shipment