You're probably 30° or 40° shy (at least) of the temperatures you would have to hit, and you'd have to maintain that contact for an extended period. Just keeping the water hot enough to sanitize, you'd spend more in energy costs keeping those temps that just using a small amount of Star Can. There's also some brew gear (like racking canes) that you wouldn't want to get that hot for an extended period, unless you want to melt them.
Given that you don't really need to use THAT much Star-San, and that you can re-use it as long as the pH stays in range, I don't see any real reason to futz around with much else. Iodophor if you prefer it, otherwise Star-San does what it's supposed to do for not very much $$ per batch. A lot cheaper than wasting five gallons' worth of ingredients due to infection.