^What about 2L or 3L years, are they more flexible with scheduling? Oh, I didn't know about the ABA limits, but it was the same on my college campus, 20 hours max. I had mandatory breaks during the hours I worked, so it always added up to less than 20
You'll get to pick your own classes your 2L and 3L years, but scheduling is a crap shoot. Some people will take classes just so they can have a certain schedule (such as no classes on Friday), while others take classes they want to take regardless of when it is. Plus, your 2L and 3L year can be even more crazy than 1L year because of other commitments outside of class, such as being on a journal or moot court.
I know several students at my school work in the library (possible as a 1L), or work for Lexis/Westlaw or as a TA (only as 2Ls & 3Ls). They get paid but can still do school work.
But I agree with kalvano that getting good grades is better than working unless you absolutely have to work. If possible, try to work as much as possible this summer and save as much money as you can so that you don't have to work.