You could check out Alcap electrolytic capacitors from Cricklewood Electronics on ebay. They work and sound fine, without costing the earth. I use them myself.
You shouldn't find the bass inadequate with the 5702's. Could be a room acoustics or placement issue.
The HF2000's can be fragile, but they'll go to useful levels, just don't go mad with the volume control. They should be less vulnerable in the B&O's, as I think the crossover point is higher than the Ditton 44's if I recall.
It is impossible for anything digital to sound analogue, because it isn't analogue!