I'm no expert on tis but I would suspect the i7 will be better than the i5 even though it is nominally spec'd slower (2.4 vs 2.8).
It depends if design is all you do, most tasks will only use 1- 2 cores in SolidWorks so in theory the faster nominal speed i5 would be better.
However simulation and rendering use more cores so the i7 quad core would be best for this.
This is complicated by Intel Turbo boost, this turns off unused cores automativcally and speeds up the remaining ones (when heat allows) There is only 100Mhz difference in the max turbo speed of the i5 and the i7 so there shouldn't be much difference even for task that use 1-2 cores. My own quad core laptop can often stay at its max turbo speed for 4 cores of 3.5Ghz for a long time and sometimes higher for less cores upto a max turbo of 3.7ghz for one core.
See specs for your suggestions here including max turbo speed. (usually quoted for 1 core,)
Thanks a lot for all the answers.
Seems like the i7 is the slightly better choice. The price is the same but i7 also has a 256gb ssd instead of 180gb on the i5.