Hot hot do you intend to run the chamber? How tiny is the printer?
Usually, it takes a high temperature on the bed to ensure the first layer of the pint sticks, and a warm, but much lower chamber temperature to avoid print warping and delamination. All this generally applies to printing ABS and maybe PC. PLA can be printed at room temperature, bed and chamber. TPU likes a warm bed.
It is generally more useful to have a bed heater and no chamber heater, than to have a chamber heater and no bed heater. If you have a bed heater you can insulate the chamber and it will warm up for the heat thrown off by the bed heater.
You need the right surface on the bed, too or you'll have trouble getting prints to stick regardless of temperature. PEI works well for most materials.
You can always bolt a couple resistors to a metal plate for the bed heater if you can't find a heater that's small enough.
Ultra MegaMax Dominator 3D printer: [
drmrehorst.blogspot.com]