There are differences between the Beta Bass and Beta Lead in the EQ frequencies, in the Bass they are about an octave lower. The condition of the caps depends on how much the amp was used and how it was stored. If you were going to take the amp on tour, a cap job would be required for the sake of reliability. There are a number of small non-polarized electrolytic caps that usually go bad as well as the main caps in the power supply and power amp. The speakers you mentioned are probably ok for a normally tuned guitar, but if you tune down to C, they'll probably fail.