I brew 2 gallon batches and sprinkle my yeast onto the cool wort most of the time. My last six batches showed signs of life in less than eight hours and were bubbling along excitedly in under 24. I saw movement in my last batch after just 2 hours. 7 batches ago, I used a liquid yeast that was expired. That beer took 48 hours to start. It was a lager yeast, but honestly, I think it should have started sooner since it was a steam beer lager yeast and my fermentation temps were purposely higher. The beer turned out ok, but wasn't one of my best. I used the yeast cake from that beer and fermented cooler to make a märtzen, which started right up and was great. So anyways, I think your beer will turn out fine, but definitely pitch your yeast based on the calculators, except that the amounts get to be kind of silly for bigger beers, but for five gallons of 5-7% two 11.5g satchets are not unreasonable IMHO. If you go all grain or save your yeast, you'll easily make up the cost of the extra yeast. People swear by rehydrating the yeast and I do it with Danster yeasts because that manufacturer recommends it, but if I'm using Fermentis I just sprinkle. Fermentis' directions say that their yeast can be sprinkled. I guarantee that someone will "correct me" on this thread, but seriously if someone believes they know more about US-05 than the manufacturer...
Have fun, I loved my first beer, I am certain you will be pleasantly surprised with how yours comes out.
Btw, don't buy bottles. If you and a couple friends can't get together 50 bottles in 3 weeks, thats a sixer each per week, you joined the wrong hobby bro. Mostly kidding, many brewers don't drink that much, but I'm absolutely sure you can find someone near you to throw themselves on that grenade for you if ask them to rinse and save their bottles for you. My favorite bottles as far as utility are Redhook. The prettiest bottles look like little wine bottles from Boulevard, but that would be an expensive 50 bottles. Don't use flip tops unless you plan to change the gaskets every batch. I found out the hard way that those bastards start to leak carbonation after the first batch.