Step-up Planning

I now own a PA28R201T, Piper Turbo Arrow III. It is a great plane
(although, as some of you know, I have had more than my share of
"challenges"). At altitude it cruises at 170 knots. Cost to operate is
around $90/hour (figuring maintenance and such). My range requirement
is 660nm with 45 minutes of fuel left offer. I most often fly it
single-pilot IFR. Lately, I have begun thinking about the next step up,
which I am planning for 2 years from now...but one can't start too early
to consider options. So, here are my goals.

Range: 600nm with IFR reserve
Speed: 250 knots or better
Ceiling: 25,000 or better (Pressurized Cabin)
Passengers: 4 seater
Operating Cost: Would prefer round trip, 1320nm, cost less than $1000
Budget: $500K

Suggestions would be most welcome. I would like to narrow the search
down to 2 or 3 that comes as close as possible to my requirements. Is a
turbo-prop out of the question? Thanks in advance.

-Sami
N2057M, Piper Turbo Arrow III