I think at minimum you will want to find out the motor class you want to race in (21.5T, 17.5T, etc) and find the appropriate ESC that will be able to handle it. For the most part, even the basic ESC's can handle up to about 13T in blinky (no electronic timing) mode.

The other is the 2S Lipo and charger. You can probably still use your radio, receiver, servo no issue. You will just look ancient with the telescopic pole sticking up. But no biggie. At least you probably wont have crystal frequency issues.

I still have my ancient JR R1 and R1 Pro radios with ZPCM, PPM receivers, along with about 20+ side by side NiCds that still hold a good charge and a box full of brushed mod motors. I use the batteries week nights on my older chassis along side NiMh sportpacks as I can keep them charged without issue unlike Lipo's.