When should I book car WDW-Port-WDW for April?

[alldiz]

Hi,
I will need a car to take me from WDW to Port Canaveral on 4/17 and then pick up on 4/21 back to WDW.

This is Easter break.....should I book now??
Who should I use.....I'm looking at an ad on this page for FL tours??? Are they reliable.

Also....I think Ship (Sensation) arrives like 7am....What time should I say for pick up If i plan on getting off ship ASAP. Hey I'm going to Kidani
Thanks
Kerri