I'd seriously look into the 300 and Falcon 50. I've dealt with 4 owners who sold out of their G200s, they didn't like it and the pilots didn't like it, fwiw. And while I love Gulfstreams like the IV, I'd think twice about buying a plane as large as a IV with its maintenance and fuel costs. The 50 has great performance in the mountains and good fuel burns but the 300 will probably do just fine and offer a larger cabin which in the end trumps everything.

Plus the 300 is a new design and could do excellent with charter if you ever opt for it because its a direct replacement for Flexjet. The 300 was also impossible to get your hands on 2 years ago, take a bet that if the economy booms eventually that it'd be the first plane people run too.

Where are you getting your data info? I wouldn't be concerned about payload at max fuel and so forth until you get some real data. Don't measure a plane based on one goes Mach .81 and the other .80, or how many pounds one can carry with full fuel. You've got to measure it against your mission profile.

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You're not getting strung along by someone are you? I did a lot of research in the past on buying airplanes for people who just talked too much and then on the flip side I did a lot of demo work a super super midsize jet for a manufacturer and was surprised by how many weren't serious buyers. Even after signing papers, throwing money down and getting everyone around them giddy about their new plane they just ended up pulling the plug. And that was in the good times with people who "qualified" which for a super midize jet was someone making around $60 or $80M and up.