Some questions on winrates, bankrolls, moving up, and stuff

[Rasputin]

First, a brief history.

A little more than a year and a half ago I started playing online SnGs at Stars and got to the point where I was pretty decent. I branched out into limit ring games, it went horribly, and I tilted away my whole bankroll which wasn't all that significant in terms of absolute dollars. I took a little vacation then tried it again, and read SSHE and combined with some bonus whoring and a decent MTT finish, I built my bankroll and gave limit ring games another try. I have come to the conclusion that they aren't for me. Without a major tiltfest, I find myself barely beating the .5/1 games at Party. More to the point, they frustrate me to no end. I've switched to NL and it feels much more comfortable.

My bankroll is about $1500 but I started at the $25 NL games to get the hang of it before moving into deeper waters.

I read in this thread that an 8 PTBB/100 winrate is sustainable by fairly decent players.

I've got about eight thousand hands logged in PT and have been bouncing between 8 and 11 PTBB/100 for the last four thousand or so. I assume that eight thousand hands isn't enough to have reliable data. What is? In the limit discussions they talk of ten thousand as an absolute minimum and some talk of needing as many as 100,000. With variance lower at NL I would think you would need fewer hands. Anyone have a good rule of thumb I can use?

According to this thread and this thread I am ridiculously overbankrolled for this level, and I would like to move up as soon as I can.

The thing is, I seem to have developed a bit of a mental block about the $50 NL. I've taken a few shots there and been rudely spanked each time. It has gotten to the point where I go in expecting to lose my buyin and that's a self fulfilling prophecy of doom.

I'm fairly certain that I am good enough to play successfully at the $50 NL level. I have a hard time believing there's that much difference between the 25 and the 50.

Basically I need to convince myself that I'm good enough and to do that, I need to look at the math regarding bankrolls and risk of ruin and all that fun stuff. Does anyone have a decent way to judge the likely results of a higher level based on play at a lower level? Something like "If you're beating the 25NL for 9.27 PTBB/100 over 25k hands you're good enough for the 50NL"

Anyone?

I've found fimbulwinter's post in this thread and it helps but I was hoping for something math based. I'm guessing there's nothing like that out there, right?