8720 motor --> alternatives

I am new on this group and I am looking for a motor for older Technic
models. The part number on manuals is 8720. This motor is not still on
trading.
Can I use an other new motor?
The most packs with 8720 i will get on e-bay are without the rubber band
(You know, the connection between the drive gears or wheels)

Tom

PS: hope my english is good enough for the expert words