I would agree with b2n2. Most places will not entertain your request unless you hold an FAA IR because of your level of experience. I suspect most of your XC time will probably not count in the USA too (FAA: 50nm airport to airport).
This is a route I planned a while back for about 100hrs/28 days:
100hrs Hour Building - Google Maps
I ended up taking a truncated route which went via Salt Lake City and lasted just under 40hrs in a C150.
I was regularly up at 10,000ft+ AMSL and landing at DAs at 6,000ft.
If you end up taking a C150 into such conditions, then watch the loading!
I would encourage you to get the experience as I learnt a lot. I would however, not recommend the school I rented from.
Some teasers:
Death Valley
Yellowstone
LAX approach
LA Downtown
As for the G1000: You should get a minimum of a day's groundschool from a TAA approved establishment so you know how it works. The G1000 WILL make you lazy and nothing beats compass and timer on an 8-hour leg!