My Lovely Horse,
First, as others have mentioned, the advice you are requesting here is well beyond what could be considered "reasonable" for PPRuNe. You would be well advised to find a trustworthy IT consultancy*, otherwise you will only end up throwing money down the drain if you try to do things on the cheap by relying on advice Joe Bloggs on some forum gave you.
As for cloud/online/whatever you want to call it services like Google Docs/whatever. You need to come to your own conclusion on this one. Do not be swayed by the marketing hype and client testimonials. For example you need to consider exit routes ..... some services may make your life difficult when trying to get all your data off in bulk. But there's far more to consider than exit routes and it's not something I'm going to be writing up here for free.
*= When looking for an IT consultancy
DO NOT be swayed by lists of fancy sounding accrediations (e.g. Microsoft Gold) .... all this means is that they've got good sales reps on team. The IT industry is all sell, sell, sell when it comes to manufacturer accreditations. So you would be best advised to use more traditional means to find a good consultancy (e.g. word of mouth).