I've still got the dash and heater in mine, I have put plastic windows in and removed the door cards, I'm looking around for some suitable plastic to make new ones with
I get some sheet at work called correx it's just like single thickness cardboard but made of polypropylene so waterproof , tough and lite . would have used on mine but already got aluminium door cards
With the heater matrix you could fit a T7 Design heater like Hummuh did and I've copied, fitted one myself with a air duct going by the drivers side but I can't test it yet to see how good it is. Gives a good amount of air flow tho, I would say setting 2 on normal heaters. http://www.t7design.co.uk/index.php?main_page=index&cPath=65
No dash in mine. The early MK1 is pretty clean under the dash pad though. It is kind of hard to hide the wiring but it is a race car and having the wiring in plain sight makes alterations much easier. Screen is heated so I don't need any blowers for demisting. All telemetry is via the Race Technology Dash2. (Steering wheel cover is for transport only, it keeps the suede nice)
My Polo 6 R race car runs a custom made Carbon fibre dash looks great weighs in at less than 2 kilos compared to a full dash at approx. 30 Kg . I think it would fit most VW cars anyway , BUT the manufacturer is in South Africa would need to cost bringing a few over here . they are approx. 400 pounds there . not sure about duties and freight . Il;; try to get a picture , but struggled to load a pic on here last time
Dry sump tank is in the box. Local race regs are such that I have to have the tank enclosed if it's in the cabin. Full build is on VWWatercooled. http://www.vwwatercooled.com.au/forums/f55/another-wreck-another-race-car-23140.html