Our Company recently designed and manufactured new type of build plate to upgrade popular Prusa i3 variations from various sources. This plate works with a silicone heater, for fastest heat up, or it can be used with MK1/MK2/A/B types of PCB heaters. 3-point level adjustment is possible with this plate when used with silicone heater. This plate is a GPL open source design, it is published on the thingiverse.com
The plate can be purchased as a short kit, full kit (with heater), and complete upgrade kit, together with aluminium Y carriage plate.