What is more important to look for in a laptop? Processor? Ram or RPM Hd?

I am looking for help in purchasing a laptop computer. I’m comparing these 2 models
Lenova G780-21824mu which has and I-5 processor 6mb ram 500gb Hd and 7200 RPM 17.3″ screen for the price of $599 or Lenova G780-21824JU which an I-7 processor 8mb ram 1 TB hard drive with 5400 RPM 17.3″ screen for $749. I need my computer for home office only. That is basic programs like word, excel, quickbooks and not for gaming or video. Does the RPM give me a faster performance for my type of work or do I spend the extra $150 for the faster processor with lower rpm? Any advice?