Having said that, if you want to wait to pay until after you have seen a fully working prototype of Jupiter you are more than welcome to do so.
That's all nice, but will that mean getting your miner later? My order is well in the 3xxx range, so will there be a difference in the time of delivery if I pay after you have demoed the Jupiter, as opposed to paying immediately after you open the orders?All in all though I'd much rather travel to Sweden and pick up my unit and transfer most of the money then, in form of BTC - perhaps after paying a certain percentage to reserve the unit to reduce risks on your end; but that being said risks and the amount of time it'd require to do this en masse would probably make this option impractical and/or impossible.
Picking up the Miner and pay them in person in the form of BTC is cool and paying them a certain percentage to reserve a unit is another good point before the unit is ready for pickup.
This^
I think a reservation fee of 10% would be a much fairer way of doing things if you are going to open up the order book any time soon. This reduces the exposure, especially for those of us considering buying multiple units. A 50-60k risk is a huge amount. 5k while harsh is more bearable. Even with your guarantee there is nothing to stop you liquidating the company and leaving everyone high and dry.
Also you should arrange to take direct credit card payments. In the UK, we have buyer protection for up to six years under section 75 of the consumer credit act. This is not applicable if you go through a third party ie paypal. As long as we pay at least £100 directly to you we are covered for up to £30000.
Things like this would give people a lot more peace of mind. Lets not forget many people have been ripped off before. The more you can do to mitigate that the better for everyone, yourself included.