There is a huge thread dedicated to this car and yes everyone is having trouble finding parts. There is an issue with parts flow but there are also links to shops that have parts and parts from other cars that will fit. Check out the Serpent S400 thread.
About your other question the car is not obsolete. It is very capable as long as um,,,, yeah as long as you can find parts. Run it in VTA or something with less breakage and get something like an X-Ray or a Photon for your hotter laps.
www.battlefieldraceway.com Racing videos at http://www.youtube.com/snoopyrc