no, just get a hold of some Rx2 chips. Your distributor may not have any idea of what they are, try asking for P89C51RB2, P89C51RC2 or P89C51RD2 if it is Philips, if it is Atmel then it is T89C51RB2, T89C51RC2 or T89C51RD2. Philips also have some lovely ISP chips in the P89C66x series (x is 0, 2,4,6 or 8). ISP for the AT89C51 (i think that is the one I'm thinking about) is a nightmare, you need two processors ganged to do it.