Simple audio vario + averager?

I'm about to replace my Peschges VP3 glide computer (which, if anyone wants
to make an offer, has the two-seater dials as well and (sort of) works).

All I want is an audio vario + an averager display. I don't want Speed to
Fly or Final Glide calculation. Ideally, all in a 57mm cutout (then I can
fit a turn and slip to the 80mm cutout left free).

So far my choices appear to be the Borgelt B40 and the Tasman. Both come in
at about GBP 260 + taxes (around 400 euros).

1. From the comments I read the Borgelt is very good. Can anyone confirm
that I can fit a toggle switch so that the needle shows 23 sec average
rather than current lift/sink?

2. The Tasman is pretty new. Does anyone have experience using one? Is the
sound musical or annoying? Is the LCD readable in sunlight?

3. Are there any other options at a similar price which I should consider?
I've already rejected the XK10 (needs two dials) and the Clever Box (too
clever by half). I used to fly another glider with an Ilec, but the SC7 is
more expensive than the two above and 80 mm.

All comments gratefully received.