This is what i used to use and how to make it
Take a poly box of appropriete size and put in a heat mat to cover the base of it.Insrt a couple of poles into the box at about a third of the way up and then place a box on these poles.Fill the box to about two thirds with sphagnum moss or vermiculite(dampened) and put a thermometer in the box.Now all you need to do is adjust the stat untill you have the required temps.
Here are some pics of how i did ours
This is the outside of the box
This is the inside veiw with boxes
This is the base view with the poles and heatmat
I hope this helps for now.I have found that incubators can be expensive and hard to come by so i made 2 of these but will be getting a converted bottle fridge this year.
The total cost of making this was around £40
Now i use a converted bottle fridge
:2thumb:WICKED MATE THE FRIDGE JOB, GONNA TRY MESELF WHEN GET DECENT FRIDGE/GLASS DOOR