Seems like an old post, so perhaps you've already found a solution.
But as for a Vocal booth, you can make a really cool DIY booth for about $200,
which is gonna give amazing results. Moving blankets are great, I've used them in the past,
but they're not as effective as fiberglass/rockwool.
If you can get yourself a bag of rockwool, and some 2x4s to make a sturdy frame, you
can get a sick booth. It'd basically be building 3 gobos, and placing them in a way
to make a vocal booth (its what they have in almost all studios). If you have any questions about
building gobos feel free to ask, there are also some great links online on how to make them
for about $25-30 per unit.