Custom spreadsheet solutions which survive long after the developer has "left the scene", are often those which users accept because they discover it _ among other benefits _ makes their work quicker and easier to do. That is why the best person to develop such solutions tend to be one who works in that area, and is therefore familiar with the way the manual system operates. S/he would have an "insider's" perspective of the best way to introduce automation other users will readily adopt _ even as it solves the identified problem(s).
Deciding What Spreadsheet Application To Use. This would ultimately be up to you. The big "fight" has always been between Lotus 1θι and Microsoft Excel. I started out with Lotus 1θι back in 1993 and learnt Lotus Macros programming(via self_tutoring). I eventually used this skill to develop _ in my free time _ various custom spreadsheet solutions(that were formally adopted for use in the departments I worked in as a brewer/manager in Guinness), before switching to Microsoft Excel in 2001. Subsequently, I developed my Excel Visual Basic spreadsheet programming skills (also via self_tutoring), because the company had chosen to adopt MS Office during the roll over to year 2000.
The intelligent use of spreadsheets, combined with the application of the 80ᚼ rule will help to achieve the foregoing and more. One does not need any expert to start doing these things today. Just take the decision to start keeping daily, accurate records and commit to analysing them. You'll be surprised to find that you will soon become much more aware of how you're doing and what aspects of your business you should focus on more to get better returns for your efforts _ and you will be able to confidently supply verifiable/authentic financial data to back up any claims you make about your business performance to bankers or prospective investors.
So, (when considering the automation I speak about) do not think about spreadsheet documents containing one or two click_able buttons that allow a user print a page or copy some cells from one sheet to another. Instead, I want you to picture an application(or Entreprise Information System) that customises the appearance of your spreadsheet workspace(to take advantage of maximum screen capital available on your PC), and offers you custom "floating" data entry forms.