as far as the tool goes-
Although it does depend on the locksmith themselve- im sure if you went in and told them you purchase many of these padlocks and would like to purchase a tool to do it yourself, most would be willing to order one. i don't think they are cheap- i can look up the price on one tommorow at the shop.
as far as the picking- the pins will not neccesarily bind the same. chances are very high that they will not. so you would get practice with finding which bind by using these similar locks.
with the pins being the same though- you will be working with the same combination of high/low pins- so you will probably be used to working around that particular set up- which wont be what you run into on other locks.
so you may benefit from keying them different- but it also matters if you plan to use these locks for.. locking, lol. in that case you might want them all keyed alike, or you could always use the same two keys (tension and pick) to get into them
with using the tool- i dont think i mentioned that ideally, you will place the padlock upside down in a vise- with the lock closed (as it comes) with the shackle locked in the vise, the padlock body flush with the top fo the vise. after setting the key, you turn it to test it, and assuming a good set, it will pop up towards you (opened)
it's helping a lot.