My interest is mainly Jazz. a) Is the GK150S combo a good amp for the D/B? b) Would two seperates give a better D/B sound than a combo? c) What makes of amp. top are specifically designed for the D/B? d) Are the smaller speakers of today as good as their bigger brothers of yesteryear? e) What construction (Wood?) of a cab. is the best for the D/B? Your knowledge most welcome.