Which computer/vario?

If starting a completely new panel, but already having a Volkslogger and
an iPAQ 3850, which computer and vario systems would people recommend?
Which software for moving map etc.?

Is there a difference between optimum for competitions and optimum for
non-comp flying? Does the country of use (UK) make a difference to
preferences?

Any views on other instruments etc., e.g. PC EFIS, DG's DSI system, or
any other new(ish) developments?

Which radio - Dittel, Becker or what? (Use would be for occasional
contact with ATC as well as normal gliding use, but usually only a small
numbers of frequencies on any one flight.)

Chris N.