Orlando is central, so the distance to either coast would be about the same. The Gulf coast is warmer and the water calmer than on the Atlantic side.
If you choose to go to Daytona Beach do not take the I-4--It is a nightmare of congestion. Take the Beeline (I think they have changed the name to the Beachline) to I-95 and go north to the Daytona area. The Beachline (Rte 528) is a toll road but well worth it. It may look longer on the map but you will move along quickly. On two occasions we have spent a month in a condo in Daytona and only made the mistake of taking the I-4 to Orlando once.
As you approach Daytona, take the Port Orange exit and go right out to the coast. There is a public access to the beach near the end of the bridge and there is a long pier right there with a restaurant on it.