Cessna 15X for heavy guys

Hi guys,

I'm a student pilot with about 26 hours, learning to fly in a
PA-28-161, Piper Cherokee Warrior.

It's a great plane, I feel comfortable in it, but I've looked at the
costs and see that I couldn't afford to buy one. I'd like to build
time after I get my PPL, so I investigated the flying situation in my
new town (Eugene/Springfield Oregon) and found that there's one flying
club with a 172, but it seems to be more expensive then just renting
from the local FBO ($93 hr wet plus club dues versus straight up $93
wet), and I can't afford to punch holes in the sky at $93 an hour. At
least, not as often as I like.

I want to fly every week, more often then that if possible. I've been
taking two lessons a day, one before work and one during lunch usually,
and I could maintain that type of flying for a long time.

I know that up to a certain point, it's cheaper to rent, but around
now, a Cessna 150/152 or Piper Traumahawk is starting to look pretty
good as a starter plane to own so I can work on practicing.

It looks like I could get one of the three as a straight VFR plane for
around $20,000, and I can scrape that sort of cash up if my wife lets
me.

The tricky part is, I weigh 250 right now, and expect to be around 220
by the time I could buy the plane (I was 330 a year ago, so it's not an
unrealistic target).

With that all out, I see the following obstacles:

1. Getting qualified in a new plane. Since I might go from a low wing
Cherokee to a high wing 150/152, I guess there would be some real dual
time needed to get everything down. Unless I can find an instructor
who's wafer thin, I could see this being a complication.

2. Making it worth while. Without having to worry about aircraft
loans, what's a realistic $$$ figure these days for flying? Say I do
100-200 hours a year, is it reasonable to manage total costs of $40-45
an hour? Is that on the high or low side? (figuring gas, tie down
fees, insurance, inspections, saving for the tear down, mechanical
surprises, etc)

3. Flying alone as a 220-240lb person, would a 150/152/Tomahawk be ok?
I climb at 800-1000FPM in the Piper Cherokee, and I'm sure it'd be
slower in the 152, but how much worse? I'd hate to spend the first
half of my cross-country flight climbing.

4. If I wanted to put some extra money to find a plane in this class w/
IFR stuff so I can work on that rating next, about how much does that
usually add to the cost? How often do these planes actually have IFR
stuff?

I've researched and researched, and most of the cost of ownership
number breakdowns I've seen on Usenet were 5 or more years old.

I have the bug, what's the prognosis? Will I live free with my own
plane I can blast around in? Or will I be shackled by the chains of
FBOs forever?