My condolences for the loss of your brother.
Congrats on your mother gifting you her machine! I love it when a machine has a family history like yours. Switching back and forth shouldn't be a big deal, probably 15 minutes to change from one to the other. I don't know if you're familiar with Singer model 15s but they are great machines for piecing and quilting. You should get many years of enjoyment from it.
Rodney