Hello Miss Rose, I am a sola traveller with my dog Millee, I do have to remind her from time to time she IS a dog :) happy travells Miss Rose. Patty.

Welcome Rose,

There is a 12v electrical system to raise AND lower the roofs, however I have only heard of one being installed, one of the GN's had it installed in their pop top on their campervan before they sold the van.

I believe it was not cheap.  It was installed by Dove Campervans in Welshpool (Perth) I am sure if you rang or emailed them they would be able to give you more details of the system they used and the price etc, I know you are on the other side of Oz but if you know what the system is you might be able to get it over your way somewhere.

Here is Doves conversion website with phone and email address;

http://www.dovecamperconversions.com.au/ 

Contact details;   http://www.dovecamperconversions.com.au/contact.php 

Edit:  This is some brief info, hoping to get some more though;

"Its an electric actuator with an up and down switch. The price is usually around $2400 fitted depending on the vehicle."

I would imagine it is something like these in the pic's and the one showing what looks like an RV bed lift using an actuator;

https://www.google.com.au/search?q=electric+actuator+12v&tbm=isch&tbo=u&source=univ&sa=X&ei=IPMOU52eG8nClQW8y4CoBw&ved=0CHUQsAQ&biw=1067&bih=496 

Trouble with the airlifters is they lift the roof but don't help lower the roof.

Struts are ok but if the load is too great they too can be a problem (eg; a bed with a foam mattress may lift easy, but add an inners spring and they may struggle unless heavier duty struts replace the others).

If you look at the picture I put on an earlier post here, it looks like there are struts under the bed as well as the electric actuator, suggesting the struts may not have been up to the task.

I am guessing the electric acutator's which have a switch to raise and lower pop tops/beds etc would be similar to those electric bed raisers hospitals use.

Here is a simple method that I used in the past;

With pop tops,  Jayco caravans have a lever (fulcrum) type frame at each end of the pop top which makes it very easy to put up and down (making sure the van door is open to allow air pressure adjustment), however some other makes like Coromal etc don't have these, just a couple of drawer type handles on the ceiling and are not easy to put up/down.

I have had both types of vans.   What I did with my Coromal was to push up with my head and shoulders (I am tall) once your start the momentum the springs and struts will take over.  If you are a short person you can use a small step stool to get some height.   What I used to pull the roof down on the Coromal was a skipping rope (cord) type configuration with a snap on hook (carabeena type) at each end.  I would hook one end onto a handle then the other to the other handle. 

The rope (cord) would be of a length so that when attached to the roof handles it would hang down in a loop about 9-12 inches above the floor.  Grab the two handles with your hands and put one foot in the loop, then start to pull on the roof handles and at the same time push downwards with your foot on the loop.  Once the momentum down starts the poptop springs and struts take over.  This method can also be used on pop top campervans.   Worked for me...