Regarding your original question, the L3010 on ebay is the same general size and HP as the L3130 you already own, only one generation older. If you want to downsize, you'd need to look at something in the B series, which are quite a bit smaller, but should handle a 5ft cutter OK, as the other posts indicate.
Kinda curious, though, what you would figure to be doing with a skid steer if you're only using the L3130 40 hrs a year.