Firstly I would look at getting flights booked. Currently, flight prices are still expensive compared to previous years. Consider connecting flights from Glasgow/Edinburgh that could be cheaper, and also flights into Tampa rather than Orlando.
That said, there have today been some extremely cheap air fares on offer through some Irish Travel Agents, but these involve getting to and from Shannon/Dublin. For example, I have seen a Shannon-Gatwick-Orlando, returning Orlando-Manchester-Shannon for around 700 Euros, and that is travelling PE (Premium Economy) UK-MCO and return. I understand that on the return journey, you
could request that your baggage be checked only to Manchester where you could then get a train back to Glasgow/Edinburgh, and not take the subsequent Manchester - Shannon flight. You would still have to book a single flight (plus baggage) from EDI/GLA to Shannon, but this cost plus an overnight hotel would still be considerably less than paying PE from the UK to Orlando.
However, I would be a little wary of this strategy should, for example, if the return flight was overbooked or delayed, Virgin could in theory re-route you on Delta to travel Orlando - Atlanta - Dublin, and hence you could end up paying a small fortune for flights back to Scotland on the day you land.
As for accommodation, onsite can be pricey. We have been fortunate for the last two visits (and our August 2014 stay) that we booked and got the free
Disney Dining Plan with our stay at Old Key West. This worked out at approx. £175/night for three of us but we do have most of our meals at Disney covered.
A quick check on the Disney website for 2 weeks arriving 15/07/14 at All Star Sports is £1176 (approx. £83/night) for accommodation which would give you the benefit of the Extra Magic Hours in the parks and use of Disney Transport direct from hotel to parks. If you rented a car, you would not pay for parking at the parks (approx. $15/day) and you could still eat "off-site" where prices are cheaper.
A cheaper option could be to stay at one of the
Downtown Disney area hotels which offer a frequent bus service to the four main Disney Parks, plus are within easy walking distance of Downtown Disney and the restaurants in the Crossroads area of Lake Buena Vista. I have just checked on Hotels.com and you can get a room for the same dates at the Best Western Lake Buena Vista Resort Hotel for £1,001 - if you book via the Quidco cashback site, you could get 10% cashback on this making it approx. £900 (or approx. £65/night).
(Just noticed that the same website currently have Disney's Caribbean Beach resort available at substantial discount for £1,280 for the 14 nights which is a superior hotel to the All Star Sports noted above).
Ticket wise I guess you would have to have some idea of which parks you wanted to visit e.g. just Disney and their waterparks, or combine with SeaWorld/Aquatica/Busch Gardens and/or the Universal Parks.
If just visiting Disney, the UK 14 day tickets would be suitable as they give unlimited access to the theme and waterparks, plus Disneyquest (approx. £800 for three of you). It does, however, start to get more expensive if you want to add on the other parks, for which there are quite a few permutations of tickets available. If you could give an idea if you wanted to visit other parks, then hopefully others can advise on the most cost effective options for you.
A final thought may be to look at using one of the Orlando "specialists" such as Complete Orlando or Val Ramsey at Travel Councellors, who can pull together a "tailor made" holiday should you be a little wary of booking things yourself.
HTH.