Hey Jos-T,
I just ordered accessories last night to run about 500-1000 (some components I bought for 500 units, some were cheaper and I went ahead and got 1000). I tried to order as much as I could from North America so that we will likely receive mostly everything we need sometime next week. I am planning on making an order next weekend for the miners.
I would like to go ahead and get an order in the next couple days, however some of the accessories might not have arrived by the time we receive the Gridseeds, so I'd rather wait to be sure that we have everything we need to get started. I am buying them from a reputable company in the USA to negate the risk of getting scammed, also shipping time will be short and is expected to only take 3 days. My guess is the first batch will be up and hashing in about a week and a half. After all the accessories get in, previous batches can be ended as soon as there are enough units ordered.
Thanks
Expected would be somewhere in the first half of April then?

Is it also possible to do the DIY solution with less than 50 units (I'm interested in 10-30, haven't decided yet). This because it will need it's on Raspberry Pi to control it, while it could actually be hooked up to 50 according to your OP.