Options that might work have all been mentioned. If cost is a significant factor, you’ll need to price the various airport options along with the car rental options for each airport.
We have generally found the best option to be MCO because of more limited car rental availability and higher rates at other locations, even if flight options were similar. We get a lot of flight options to MCO since we fly out of Chicago. The drive from MCO to Disney’s VB resort is very easy, 528 east to I95, south on I95 to exit 156 (CR 512), CR 512 to CR 510, and CR 510 east to the resort. There is a convenient Publix at the intersection of 512 and 510 if you want a grocery stop on the way to the resort. It’s about 90 minutes from MCO to VB, about 95 miles.
There's an airport in Vero, but not too popular. Melbourne is very close, MCO and PBI are equi-distant, one is West, one is south. Probably easier for MCO and driving east to Vero generally better than North on 95. (my $0.02)