I'm told that Sunpass and Epass both work on all Florida toll facilities but that Sunpass has better discounts for visitors.
Actually, the exact opposite is true.
First of all, toll discounts at SunPass tollbooths are given on-the-spot to everyone with either a SunPass or E-PASS transponder.
Discounts at toll booths marked with the E-PASS logo are only given to E-PASS transponder holders, not to SunPass users, and are only given at month-end based on how much was spent on tolls that month. (Over $40)
Bottom line, for tourists or occasional users, it doesn't matter which transponder you carry, you get discounts on-the-spot at many SunPass toll booths but not at E-PASS toll booths. For locals who rack-up lots of tolls each month, you're better off with an E-PASS because you get the on-the-spot toll discounts at SunPass toll booths and then an end-of-the-month discount at E-PASS toll booths based on volume.
SunPass is the state-wide system while E-PASS is the system operated by the Orlando-Orange County Expressway Authority (EA). Throughout Florida toll roads and bridges will display the SunPass logo. In Orange and Osceola County only many toll roads are operated by EA and display the E-PASS logo. In Lee County (Fort Myers) a third system called LeeWay operates on their three toll bridges. All Florida systems are interoperable with each other. And as JB2K mentioned, the Florida systems are not valid up north in other systems such as E-ZPass, I-Pass, I-Zoom, K-TAG, PikePass, etc. nor are those transponders operable in Florida.
To the O/P, you can probably get a SunPass at Publix or CVS in your area and that would be fine for the 429 and all other toll roads in the state.
BobK/Orlando