Theres some on ebay.
some that need some work here
http://cgi.ebay.co.uk/Wheel-chair-motors-and-gearbox-for-robot-or-go-kart_W0QQitemZ280290410077QQcmdZViewItemQQptZUK_He alth_Beauty_Mobility_Disability_Medical_ET?hash=it em280290410077&_trksid=p3286.c0.m14&_trkparms=72%3 A1301|66%3A2|65%3A12|39%3A1|240%3A1318http://cgi.ebay.co.uk/Wheel-chair-mo...go-kart_W0QQit emZ280290410077QQcmdZViewItemQQptZUK_Health_Beauty _Mobility_Disability_Medical_E T?hash=item280290410077&_trksid=p3286.c0.m14&_trkp arms=72%3A1301|66%3A2|65%3A12| 39%3A1|240%3A1318

or

http://cgi.ebay.co.uk/ELECTRIC-MOTORS-24V-WHEELCHAIR-ROBOT-MADE-BY-BY-EMD_W0QQitemZ130272114690QQcmdZViewItemQQptZUK_Hea lth_Beauty_Mobility_Disability_Medical_ET?hash=ite m130272114690&_trksid=p3286.c0.m14&_trkparms=72%3A 1301|66%3A2|65%3A12|39%3A1|240%3A1318http://cgi.ebay.co.uk/ELECTRIC-MOTOR...-BY-EMD_W0QQit emZ130272114690QQcmdZViewItemQQptZUK_Health_Beauty _Mobility_Disability_Medical_E T?hash=item130272114690&_trksid=p3286.c0.m14&_trkp arms=72%3A1301|66%3A2|65%3A12| 39%3A1|240%3A1318

or get a complete chair. then you have other bits you can use from it such as wheels.
BTW what sort of flipper you going for?

(Message edited by xtreme on December 06, 200