US-05 is fine and pretty much the same thing as Wyeast 1056 only cheaper so I would go with that. If you're going to try BIAB the first thing I can say is make sure you have a good thermometer. Check it in a bowl of crushed ice and in a pot of hot water to make sure it's accurate. Mashing is very temperature dependent. Also, if you're crushing your grains at the store I would run them through the mill twice to make sure you can get a good crush and good extraction.
I don't know how well you're pot maintains temp but for me I can usually add some heat at 30 minutes stir for a couple minutes and keep the temp pretty close to where it should be. As far as sparging goes, I like to have a separate pot with 175* water to dunk the grains in. Pretty much toss the whole bag in then stir it around for a few minutes before adding that to the main boil kettle and drip drying the grains above.
I hate Walder Frey...