Frode Berg wrote:

The plane I co-own is IFR ready, but has no autopilot or stormscope, no
de-ice (no options for it either I think, Arrow 180) and a Garmin 95 VFR
GPS.

What would be the most immediate need to safely fly IFR single pilot, single
engine?

The autopilot (would get a one-axis S-tec which easily upgrades to two axis
later), a Garmin 300 or 430 GPS, or a WX-900 stormscope.

Single pilot IFR? My vote would go to the autopilot, hands down.

I suppose you have much less need for it than I do, because
the Arrow is a more stable plane, but even so, it's nice to have
the ability to look at a chart, write down a clearance, or
eat a snack momentarily without having to recover from a rapidly
steepening bank.

As for other upgrades, what you get the most use out of really
depends upon what kind of flying you do. I'm not familiar with
the aviation rules where you fly, but someone in US who flies
mostly into busy airports and in radar environments doesn't
have much need for an IFR GPS IMO. He can still fly direct by
radar vectors backed up by VFR GPS. Most of the airports he's
using are served by an ILS or at worst, a LOC or on-field VOR,
so he isn't getting a lot of extra utility out of an approach
GPS.

OTOH, we fly a lot where there isn't radar coverage once one
descends for approach and the only choice to get into the airport
is NDB or GPS or a VOR 30 miles off the field.

Stormscope, similar kind of thing. What are the wx patterns
where you fly? We want it because there are wx patterns where
we fly where if for some reason one must go VFR, it's harder
to figure out the best routing and because sometimes IMC, it's
supposed to be benign but we get there and whups, there are
isolated tstorms embedded, Beam Me Up Scotty. It's at the top
of my "want" list currently, but we already have an IFR GPS
and a wing-leveler autopilot.

Cheers,
Sydney