Ever thought about purchasing a used canopy? Sometimes called a topper or me and my friends affectionately call them "can-of-pee". Lockable, has a decent seal, keeps a dry bed. Best part is that it's cab-high or higher. Used canopys can be had for as little as $100 if you just wanted something to get the job done. Ones that actually look good and made to fit the truck properly range from $200-600 and far beyond sometimes. I bought my fully optioned out Raven canopy for $120...carpet, Yakima rack, etc. I later found what I initially was about to purchase from the dealer pop up on Craigslist locally. It had lift up side windows instead of sliders and that I really really wanted. Leer 100R for $300. MSRP on it was $1400. Dropped $150 on paint, sold the Raven, and here I am with a practically new canopy for a fraction of the cost. Plus, I robbed the Yakima rack and filled the holes of the Raven before I sold it(for profit I might add. lol)
Adding a new vehicle(or new to you) seems like a gross waste of resources in my opinion. Double the maintenance, double the insurance, etc, blahblahblah. But in regards to problems with Explorers......you never mentioned a year you were looking into. But you'll want to stay away from 95's for their front flaws, but after that, their reliability is the same as that of a Ranger. Explorers are based off of a Ranger, so....
Now if you were looking into 02+ Explorers, I haven't a clue but I assume they're similarly reliable like the older models. '02+ Explorers are an all new frame, IRS, body differences. Not included is 02-05 Explorer Sport or Sport Trac....those are still the same trucks as the 95-01 Expo and 98+ Ranger.